I have Teams working smoothly bybusijg the WebApps thing, launching a single Firefox (which is not my primary browser).

I then have 2 profiles, and Teamsnis a pinned tab in the Work profile (other chat webapps are pinned tabs in the personal profile). So all those tabs in various profiles are opened in this one window, which I then call "Chat Apps" in the launcher. I make the Firefox UI completely autohide except the titlebar and side tab bar.

This works flawlessly for all sharing and calls and notifications. And if I wanna be done with work I can close or Unload(hibernatr) the Teams tab.

Anyway, if you don't want the whole tabbed thing, you can try to use the web app thing to launch teams in web mode that has so far worked better than any package I've tried.