I am on latest RouterOS v6.44.3 and Routerboard firmware 6.44.3

I have 3 SSIDs configured via Quick Set "2GHz", "5GHz" and Guest Wireless Network. Normally, all 3 work fine, but once in a while "2GHz" and "5GHz" stop working. At the same time Guest Wireless is working fine and ethernet is also working fine.

Additional symptom: When this happens, if I connect to "2GHz" or "5GHz" and try to access the router from browser, instead I get a screen with Mikrotik SwOS and basic auth popup.

Any idea what could be the problem?

P.S. Trying forum before reinstalling with netinstall

I had another device with static IP 192.168.88.1 in the network. It was a mikrotik switch with default settings.