I see that Zoom in 4.6.9 removed some permissions required for virtual camera. We will contact zoom to fix the issue.
In the mean time try out old versions (I haven’t tried them though, so please share your results):
- 4.6.8 (March 23, 2020) https://zoom.us/client/4.6.19178.0323/Zoom.pkg
- 4.6.7 (March 1 , 2020) https://zoom.us/client/4.6.18176.0301/Zoom.pkg
- 4.6.4 (January 19, 2020) https://zoom.us/client/4.6.17383.0119/Zoom.pkg
This is actually an issue with macOS sandboxing, if you want you may submit feedback to Apple and ask to provide a way for virtual web-cams to work in hardened application: https://www.apple.com/feedback/macos.html