choppy video playback
Using the latest flatpak artifact, the video playback is quite choppy, on 1080p 60fps and 720p. On lower resolutions of online video, it works fine. This happens on YouTube.
example video to reproduce issue: watch https://www.youtube.com/watch?v=LXb3EKWsInQ in 1080p or 720p. Not only is the video very choppy and laggy, but all animations on the page slow to a halt too, and so does Epiphany scrolling and zooming... Maybe this is related to the Media Source Extensions needed for high resolution youtube?