I had the same problem.  When I rolled back to the previous (prior to Oct. 2021) audio driver it corrected this issue.  It also corrected other slow computing issues I had been having.
Hi!  My integreted webcam has not been working for a couple months. When I open the camera app, zoom etc. it just shows a black screen.  I tried all the Windows troubleshooting, and the Windows support team also tried everything on their end but said I would need to contact Dell. I am 14 days out of warranty so I can't connect to a chat.  I've seen other people with this issue but yet to see any resolve? There isn't a physical cover on the camera either.  I have a Dell Inspiron 5000 series with Windows 10.    Thanks,  Sorcha 
Camera Not Workin- Black Screen