Split from this thread.
I too have a similar problem with the camera and Surface Pro 8. I use Windows Hello to log in and after the device has been left for some time the device will unlock but if you then try to use video in a Teams call the screen will be blank and it will report that no camera is present. I have run Windows update, Updated the camera drivers, and run the surface app to check the firmware is up to date. run the Surface hardware diagnostic tool. None of these found any problem.
I have updated the Teams Client, and tested with both the desktop and web client. when having the issues and the problem it present on both.
I full reboot will get the camera working but that is not possible when in the middle of a call.
The only way to fix it without rebooting is to open the device manager and disable and then enable the camera. This will normally fix the video in Teams.
We are a small company but we all run Surface Pro 8's managed by Autopilot/Intune with very little in the way of additional software. All are less than 12 months old. More than 50% of the staff are having issues with video calls within Teams after a period of inactivity.