My Mac kicked me out from Apple ID

Hello!

So randomly today I noticed that my Mac had logged me out of Apple ID out of nowhere. That has never happened to me before. I tried to log in but it said "Confirmation Failure - Unexpected Error". I decided to upgrade the system from MacOS Catalina to Big Sur but it's still not letting me log in. The password is correct, that is not the issue here. I'm still able to use Apple ID on my iPhone. Does anyone know this problem and how to fix it?