ersinerol,
How dense is your deployment? It looks like the access points are being run at almost full power. That could cause roaming and disconnect issues because the clients will hold onto access points longer than they should. You should probably reduce the ARM Minimum TX power to 12 and the ARM maximum TX power to 18. Also on your Virtual AP profiles, you should enable "Drop Broadcast and Multicast". After you do those two things, you should collect information from show ap radio-summary again.
On the 2.4ghz side of the IT.WAP.ARB105.PLT-501 radio, the RF utilization is at 38% which is high. Reducing the power and dropping the broadcasts can help that.
IT.WAP.ARB105.PLT-501 3.Kat_AP_Group 105 172.28.3.97 2.4 AP:HT:1 21/22 -96/38/8 8/5/0/1/0/1 9/9/11/11/11/10 2/1/0/1/0/1
IT.WAP.ARB105.PLT-501 3.Kat_AP_Group 105 172.28.3.97 5 AP:HT:161- 24/24 -93/1/0 0/0/0/0/0/0 0/0/0/0/0/0 0/0/0/0/0/0