Unclear wireless clients behavior

[slyfox]

Hello,

we have WLC 3504 ios 8.8.120.0 + set of AIR-CAP3702I-E-K9

From time to time, clients experience problems connecting to a wireless network. Two identical twin laptops can be a meter away from the access point and on one there will be everything OK and on the other there are communication problems.

Laptops equipped with Intel AC 9560.

Event log for problem laptop attached.

[Leo Laohoo]

A metre away from the AP ... a 3702E.
What antenna is the 3702E using?

[slyfox]

Hello @Leo Laohoo  I mentioned 3702I, it has an integrated antenna. 

[Leo Laohoo]

Only these two wireless clients having problems?
What about other wireless clients? They having same problems?

[slyfox]

At one point, a problem can be observed with 1-2 clients, but then go through and not appear at all anywhere. Replacing a wifi adapter may help. Also moving laptop btw AP also may help. 

Can AAA settings affect?

[Leo Laohoo]

And what firmware are the Intel 9560 running on?

[slyfox]

@Leo Laohoo  Intel 21.20.1.1 from 5/30/2019

[Leo Laohoo]

Try the latest driver, 21.50.X.

[slyfox]

@Leo Laohoo 
didn't help

what ERRORS at event log can mean ?

[Leo Laohoo]

Do a "debug client <MAC ADDRESS>" and log it.
What happens, with the debug enabled, and this issue occurs?

[slyfox]

Hello @Leo Laohoo 

debug info attached

[Leo Laohoo]

I've had a look and I don't see any issues with this debug.
The debug starts at "12:59:48.549" and by "12:59:48.583" the client got an IP address of "10.84.150.205".

Please expand, with more details, what issue(s) are observe when this happens?  

Do the wireless clients get a yellow "!"?  Did the wireless clients loose wireless network?  Did the wireless clients lost access to a certain DB?

[slyfox]

Hello @Leo Laohoo 

Client experience high level packet drops. It can begin as unexpectedly as it ends.

without any kind of OS changes, on the hotspot from the phone at the same time, there are no problems.

[Leo Laohoo]

Can you replicate the issue (ping drops) with, say, a smart phone?

[slyfox]

Hello @Leo Laohoo 

No,