ACER Chromebook 14 CB3-431
I had to perform a system restore after ill-advisedly setting the chrome://flags "dark mode" rendered my Chromebook unusable in all but the Guest account. Could not even initiate a Power Wash.
After the restore everything came up fine as Chrome OS 77, and updated itself to 78 as it was prior to the restore.
However the camera is now not detected. The camera app says "Your camera is currently unavailable", and Google Duo Android, Web and Chrome apps all show "no camera found". - only microphone, which works fine. There are no camera related settings in the Chromebook Settings (not sure there were before to be honest - it just worked - for three years until now.
I have tried a hardware reset. I have not performed a powerwash because I'd only just performed a System Restore, so there seems little point. It is as if the restore media omitted camera support.