You should do a decrypted packet capture on the client to see what is being communicated:
(Aruba7640-US) #packet-capture destination local-filesystem
(Aruba7640-US) #packet-capture datapath wifi-client <mac address of client> decrypted
(Aruba7640-US) #show packet-capture datapath-pcap
The "show packet-capture datapath-pcap" command will show you the traffic going back and forth to see what is being transmitted and the port. For the actual packet capture, you will need to take the logs.tar with tech support from the controller and look for the datapath.pcap for the actual packet capture so you can see what the client is communicating back and forth.
When you are done, make sure you type "
no packet-capture datapath wifi-client <mac address of client>