Sudden Issue - Few Users wifi connection says connecting to wifi and it doesn't connect

[Sai_Prasad_Rao_]

We have 2 - c5210 controllers with 3805i Access Points running on 9.21.10.0005. Everything was working well (with few disconnections here and there )all of sudden few users report "when they are trying to connect to Wifi they are seeing connecting to WiFi and they are not able to connect.

DHCP scope is fine
idle timeout settings : pre: 30 , post : 30 session: 0
Running both B@ap and B@ewc
Security: Open

Changes made in last 3 weeks : Disabled ADDBA and Aggregate MPDSU (which resolved client dis connectivity issues to a major extent)
Flexi Cleint access: Disabled on SSID's

[JP4]

When you are seeing the issue, if you look at the client by AP report, do they show connected there ? I have had a couple reports of that here and it seemed to only be 2.4 radio so far.

[Sai_Prasad_Rao_]

Hi Jeremy

As requested I have provided the radio 1 & 2 details, waiting for update from your side.

[Sai_Prasad_Rao_]

Hi Attached screenshots.....

[Jeremy_Gibbs]

What are you using for the advanced settings on the 2.4 and 5 ghz radios. Can you provide a screenshot of each?

[Sai_Prasad_Rao_]

4000+ users max Issue is same when there are 500 users connected. Each ap has less than 30 users.