I have had issues with video/audio in Teams on multiple computers, so I’m going to say its probably part of Teams.
I have used Teams on a variety of Windows 10/11 home/professional systems. Since it has existed it seems to not always pick up the correct audio or video options when there are multiple.
Besides that, it doesn’t properly identify the system audio/video options. I have been listening/talking in a meeting on headphones and Teams shows the source as on board audio and mic. Or it will not show any audio sources and still work.
For this reason I always arrive early to Teams meetings and double check my audio and video. Strangely it can sometimes choose the headphones which I always use, but when I look in the Windows Sound Input preferences it will show the system devices and not show that the Bluetooth headset is working.
I have to conclude that Teams doesn’t communicate perfectly with the Bluetooth subsystem in recognizing when they are active or not. I have also had the weird issue of it working on built in mic/speaker and then switching to Bluetooth headphones.
Just for the record, I only use Bluetooth headphones in meetings. I have disabled other sound outputs like the projector so that it doesn’t try to select that. While the projector built in speaker is adequate, I don’t want to make noise for my neighbors and so use the headphones all the time.
Windows has a weakness with audio this is clear. Sometimes you can fix this bug by restarting windows, and if you have an audio issue restarting is my first line of defense. Then look at sound output and try to limit outputs and inputs of sound if you can. Don’t buy a external webcam and try to use Bluetooth headphones or you will probably regret it. This was often an issue I had to resolve when I helped people in this manner in the past.