There is a bug that means if your password expires while logged in it can crash teams, putting you into a loop of entering a password, crash, enter password etc. Officially the only cure is reinstall (yes that is what I read in forums)
Another (may work) solution is to remove all your credentials for Teams in credential manager. I had 51 separate credentials as Teams never closes any down. After deleting them all I had a default 17 appear (what do 17 logins actually do???) It is just so badly written like every other MS product. I mean a password expiring is a real world everyday situation and MS can't understand that.
And they designed it so you can't copy folders, any sub-folders just get brought together causing carnage for some teams who were not aware before hand.