@TeamYouTube , I've had some issues with my recent uploads (today's). Videos are playing back audio fine, but video is lagging quite a bit. I've never really had this issue before; made a new file to be sure it wasn't my file. Here's the video in question: https://youtu.be/ghzbmLKiEZw
Follow up: after messing around a bit it seems that the video does work, but only at 360p. Anything lower or higher causes the video to freeze. It seems as though either it's not rendering very fast at those resolutions or not at all. Not sure if that helps.