Wireless Access

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

I have :

Allowed band : all

Allowed 5G radio: all
Band Steering: enable
Steering Mode: prefer-5ghz

Do you recommend to switch to force-5ghz ?

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

I have :

Allowed band : all

Allowed 5G radio: all
Band Steering: enable
Steering Mode: prefer-5ghz

Do you recommend to switch to force-5ghz ?

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

I have :

Allowed band : all

Allowed 5G radio: all
Band Steering: enable
Steering Mode: prefer-5ghz

Do you recommend to switch to force-5ghz ?

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

All good and valid propoals for troubleshooting.

I would just like to add for your particular case - as you mentioned it all started with the change to make use of the cluster-feature:

hope you do have a backup of the configuration from BEFORE; so it might be helpful to compare the configuration from BEFORE CLUSTERING and NOW.

RM-profiles; features (like k,v,r), etc.would be s.th. to start with

Did your SE "transfer" the old configuration one to one to the new setup ? 

You did not mention what firmware version was used before the clustering; did you switch to a different version as well ? 

------------------------------
Jochem Knoben

Original Message:
Sent: Oct 07, 2021 12:53 PM
From: marcel koedijk
Subject: Client Connectivity loss(long-term problem)

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.

Same as Collin mentioned there are many ways why clients loose a connection and work with TAC support is the best way to get it solved soon as possible. Please escalate the issue TAC or get help form your local Aruba Partner.

When troubleshooting start with collect as much as details possible, no loose ends, use only facts, and work in small steps. In the world of WiFi there are a lot of factors responsible for the connection, some area's:
1. The client
2. The access points
3. The "air"
4. The configuration
5. The supporting network infrastructure
6.  Good designs of all above :)

Start focus on clients. On which radio, which channel, which ssid is it connected, which SNR strength, how often does it reconnect, others in the same room on exact the same timestamp, etc. What about the client drivers, are the up-to-date  or not (80% of all issues), end so on. Does the issue happens on one type of client devices with same operation system and Wi-Fi chipset. Step by step, collect ANYTHING.

On windows run as administrator on the CLI "netsh wlan show wlanreport" can give you great information about the client connection and authentication.

Also take a close look at sniffing 802.11 frames from the air with wireshark, you need some expertise on this but coud be an important move to dive into.

Check all login in the wlan controllers "show ap debug" for example or "show syslog all", you could also set some debug levels for interesting parts. Also look for "DFS RADAR" events "show airmatch all-events" with a mobility master in place.

Be sure have have a good RF design in place with a reportage of it.

Be sure your netwerk have no latency etc., check your network monitor tooling.

Place some Aruba User Experience Insight sensors to monitor the WiFi user experience with backlogging of 30days.

Update your controller firmware to the latest conservative release 8.6.0.13, noted that 8.5.x.x. will go end of support by end of this year.

Replace old fasion AP's like the AP-105. Better get same type of AP's in the same area for optimal roaming.

And so on and so on; The small story here.... Hire somebody that have extended knowledge in troubleshooting, Aruba and or CWNA or Ekahau certified, and put time into troubleshoot any bit and byte.

Hope i can give you some usefull tips, but understand the answer is hard to get from the community because it's to complex for handle on the forum.