Cursor is not auto-hiding after taking a youtube video fullscreen on macOS

Whether a person clicks the fullscreen indicator or types F on the keyboard, the cursor will remain on screen as the video is playing until it is again moved. This also affects video played through the browser on steampowered.com. This issue appeared as of 143 and is still going strong in 144. This seems to be macOS specific as I am not noticing this behaviour on the Windows client. Could be a conflict with Tahoe.. I don't really know at this point. There used to be a website where you could fire off a 'Firefox made me happy/sad' which is where I would've preferred to send this. So, have other people encountered this issue? And if so, are there any lasting solutions beyond wiggling the mouse?