Hello.
There is a problem with connecting old smartphone (Philips W832) to wi-fi, provided by RB951G-2HnD with capsman and RB751U-2HnD, used as CAP. It started after upgrading firmware to 6.39.3 on bugfix channel. There is problem also on 6.40.5. Logs filled with lines like
21:06:30 caps,info 00:1D:07:D6:00:F1@cap1 connected
21:06:30 caps,info 00:1D:07:D6:00:F1@cap1 reassociating
21:06:30 caps,info 00:1D:07:D6:00:F1@cap1 connected
21:06:30 caps,info 00:1D:07:D6:00:F1@cap1 disconnected, received deauth: class 3 frame received (7)On connection status appearing message about authentication error.
Other devices like newer smartphones, tablets or laptops works fine.
Config in attachment.
Throw away this old junk is unwanted solution - its owner for some reason likes it.