Just FYI,
It's been a couple of weeks since Teams Desktop for Linux ceased its anomalous behaviour. I haven't changed anything on my setup (Ubuntu 20.04 LTS) aside the usual system and security updates.
But now the problems have disappeared. Maybe can I blame the new Teams version - 1.5.00.10453?
Anyway, thanks to the developers!
By the way, I didn't install the @KEVIN A BUHR 's script because I'm not using Teams web client.