I have reinstalled MS Teams many times, cleared all its cache folders many times, removed all Office and other credentials from Credential Manager many times, made registry changes, logged out explicitly and logged in many times. These are routine activities I have to do just to use it because my organization has a subscription and won’t use any other tool (Skype for Business was abandoned after it reached some amount of stability over several years).
In summary, MS Teams is a dysfunctional tool that reflects the dysfunctional organization behind it. I can’t think of any other reason why it should be so badly maintained.
Every time I think of Windows and other MS applications like Teams, I can’t help but wonder what big productivity and time suckers these are. They seem to be the lowest common denominator in the IT world.