Windows 11 - New Teams. I don't have the exact version number, but I did remove and reinstall the application on Tuesday during my troubleshooting so whatever version was available then.
They have an HP notebook that is docked. The microphone being used is from a Logitech webcam (920?). Output is through the notebook's built-in speakers.
Here's the exact scenario:
I have a Teams meeting with a user. When they speak, everything sounds fine. When I speak, I hear myself coming back from their microphone. I opened the sound settings on their PC. When they speak, I see activity on the webcam microphone. When I speak, I see activity on every microphone on their system.
This issue does not occur with the classic version of Teams.
I reset the New Teams app in the Windows app settings, and this fixed the issue. However, the problem came back later.