The new wireless debug page is great. Unfortunately, this one is not in there.
Disconnected, not responding.
I know this is an obvious message, but what is the cause when all 25 connected devices all disconnect at the same time and do not reconnect. Disable/enable AP interface and all connect again for a while.
AP is on 6.39.1. Clients are all 6.38.5 or higher.

Maybe related, if any client radio is rebooted, all devices disconnect with above message and do not reconnect.
What should we be looking for?

I experienced this exact phenomenon today. Think I'll set up a script to monitor the wireless registration and it it drops to zero, reboot AP.

We've been seeing this off and on for a year or so with different firmware.