Same issue here. Been tracking for a while. Worked fine for something like the first year or two I had the computer, then started happening after an update, I think to Catalina or Big Sur. It only happens when I screen-share in Team, Meet, Zoom, pretty much any of them. Or at least that's what I've correlated the issue to. After over a year of messing around with trying to fix the issue or find resolutions online, I finally gave up and picked up a new M1 MBP for work. Recently, figured I'd give Bootcamp a shot on the I9 Vega Pro 20 to do some Solidworks and gaming. Epic fail. Stock drivers or bootcampdrivers.com version give stuttery performance to the point of unplayability with pretty low settings on games as easy to run as Fortnite (which runs fine on a 2-year older iMac at higher settings). So, I'm starting to wonder if there isn't a hardware issue with the GPU - and it looks like I'm not the only one having it. If anyone has seen a resolution, I'm all ears. There's nothing I'd like better than to return this expensive machine to active service on other than just menial tasks.