Missing log entry?

I’m troubleshooting rb95ui-2hnd device that is used as a wireless access point with radius (NPS on Windows Server) authentication.
Login/password access works well, everything’s logged as it supposed to, but when I use certificates I only got 2 messages in log:

15:24:08 wireless,info XX:XX:XX:XX:XX:XX@wlan1: connected 
15:24:12 wireless,info XX:XX:XX:XX:XX:XX@wlan1: disconnected, received disassoc: sending station leaving (8)

No errors, no warnings, nothing. Logging is enabled: critical, error, info, radius, warning, wireless.

There are several similar devices in this network that have the same configuration, but this problem is with this one only. Where to star looking?