Try removing Microsoft Teams old with ApplCleaner from: http://www.freemacsoft.net
This software once installed will provide a window you can drag the Teams application directly over to remove all old components.
Then installing Teams new from:
https://www.microsoft.com/en-us/microsoft-teams/download-app
A restart may be necessary to be able to run the installer on Teams. This can take up to 20 minutes for the initial splash screen to get you to the point you can choose your Microsoft Account.
Once Teams New is configured, use the meeting invite to launch your Teams meeting.
If you have a business E3 license for Teams additional features may become available to you.