I am experiencing the same issue, although it seems to have stopped being an issue in Edge.
It's really prevalent in the official Twitter app.
Please excuse the audio, selected a random YouTube audio clip to cover up the original audio.
UPDATE: The really helpful Microsoft support advisor asked me to uninstall the current Intel graphics driver via Device Manager and to download and run the MSI available here to reinstall the latest version.
https://forums.windowscentral.com/e...ad%2Fdetails.aspx%3Fid%3D49498&token=DACcFJ0_
Sadly this didn't fix the issue but it does seem a little less severe.
It doesn't seem to make any difference whether the app is full screen or whether the device is running in "Tablet mode", as soon as the playing video clip passes under the top app bar it triggers the screen glitches.
I've also tried reinstalling the Twitter app and triple checked I have all the latest updates.
I've installed Tweetium trial and that has the same issue, only when you narrow the window to cause it to scroll the timeline vertically. As with the official Twitter app it happens when the video content scrolls underneath the top navigation bar.
I've tried a few web sites in Edge that have animated images and videos and can't get the flicker to occur.
UPDATE: The issue is back in Edge, just hadn't for a while come across a page with the right sort of embedded video I presume. It exhibits the same behaviour though, it's when the page is scrolled and the video is partly obscured by the browser toolbars.