Windows 11 beta on Surface Book 3 09 Aug: cannot switch on cameras and Windows Hello stopped working

Windows 11 beta (fully updated) on Surface Book 3 09 Aug: cannot switch on cameras and Windows Hello stopped working.

Tried everything related to devices, drivers, services, group policies, registry, settings - nothing works and my camera app gives me a black screen.  Tried troubleshooting and on-line "get help" without success.

Any suggestions would be highly appreciated.