Yes, I modified valid channels to include only UNII-1 below 50. We'll see how it changes things. There is another SSID that the client tried which also includes 2.4 GHz band, but I guess it's possible that the clients tried to connect to 5 GHz even if there were radar interference.
I read that radar avoidance can cause the whole IAP to reboot, but I'm not sure if that's still the case with current firmware, or will it just hop to another channel? Should radar interference be visible in other areas except just in log messages?
What about the fact that noise floor was -92 but SNIR was 0 db? Would that be indicative of some specific interference, or would it display that if there isn't enough data to calculate the value? There was only one dormant client connected at that time.