I went through the feedback thread and found that this had been addressed previously, but it looks like this bug has reared its ugly head again.
Version 85.0.558.0 (Official build) canary (64-bit)
Occurs when maximizing some videos.
This is a known issue to the Microsoft Edge team and they are looking into it. It would be great if you submit feedback about this with the diagnostics attached through the in-app feedback tool (Alt+Shift+I) in Microsoft Edge.