camera is off in meetings

First, check Firefox's camera permission by clicking the lock icon beside the Zoom address and allowing camera access, then reload the page. In Zoom's video settings, make sure the correct camera is selected. If it still doesn't work, test the webcam in another app on Linux Mint to see whether the problem is Firefox or the camera itself.

Thank you Malcolm - I don't know yet if this fixes my problem but I suspect that it does.