69 votesAnonymous commented
This is because Teams isn't taking control of the audio device, which is how this would be fixed. I am having the same issue.
If you go to Start > Sound > Communication, this controls what happens to your audio. I personally prefer my sound to reduce by 50%, but either that or muting will work if Teams were to take control of audio correctly.
This feature item is still in the works. We will keep you posted as we have new info from the feature team.