We are finding this issue with all newer and newly updated Macs for Chrome, Firefox and explorer where the individual is using the built in camera. I don't know if anyone tested with an external camera. I found a thread on the apple support site -https://discussions.apple.com/thread/251375319?page=1
It appears that newer settings have mac cameras set to variable rates and that appears to be causing the sync issue. I asked our host if there was a way to force/override the default settings to record at a fixed rate...they don't believe so.
I did hear from our host that there is a plugin but they have concerns about the stability.
If you like I can request a link to the plugin to share with you...they didn't provide a name just that they found one