I have a solution that is working for me so far with over two weeks in production. Taken from https://christiaanbrinkhoff.com/2020/05/29/learn-how-to-install-and-configure-microsoft-teams-with-av-redirection-media-optimizations-on-windows-virtual-desktop/
The key is to install Microsoft Teams per-machine on RDS rather than per user. The key steps are:
First we must create the following registry key in the image
Type: REG_DWORD Value: 1
Download Teams and run the command below to install Teams per-machine
Note: To use the WebRTC AV redirection client, you must use Teams version 1.3.00.4461 or later – the 64-bit version is highly recommended.
msiexec /i c:\install\Teams_windows_x64.msi /l*v c:\install\Teams.log ALLUSERS=1 ALLUSER=1
If everything ran perfectly you will see Teams showing up in the Program Files directory.