I use Windows 10 Pro and OBS Studio to virtualize my DSLR to use it as a virtual camera.
When doing a videocall everything works fine until a third participant enters the conference. Blizz crashes most of the time at the moment the third participant enters and sometimes after a few seconds.
Also when I set the camera settings to optimize speed Blizz crashes as soon, as it tries to initialize the camera.
Sorry to hear that you are facing problems with Blizz and camera: would it be possible that you send feedback through the app and include your logfiles next time this happens, so that we can investigate why this is happening?
If you have a license that supports it, you can also contact support (submit a ticket) in order to send you crash logs as well.