I don’t have a fix but I do have a temporary solution. At least it stops ringing when I am on a call.
I recently bought another Bose 700UC for work and now the problem followed me there.
Solution 1–in Windows 11, sometimes, you can click the speaker icon in the system tray. A separate “media control” panel is above, showing it is playing media. There is a pause button. Press it to stop playing. Unfortunately that panel doesn’t always show.
When it doesn’t show, press [WIN] G. This brings up the xbox game bar. It has an audio panel with a mixer. It shows all of the devices that are playing music. There are several Teams bars, but one will be the ringer. Mute it and take your call.
This is absolutely ludicrous.