Clearing the Teams cache can often fix any problems that you're having with Teams. The Teams app doesn't have a built-in way to clear the cache (like browsers do), so you'll have to do it manually using the steps in the PDF below.

How-to-Empty-the-Microsoft-Teams-Cache-on-Windows.pdf

** Note: some users may experience issues after clearing their cache. If this happens, you'll have to report it to IMS.