The issue still occurs I even checked other apps and the same happens. My connection speed is very high. I think there is some problem with an algorithm processing video after upload. When I watch it in AppStore connect first the video is small then after a few seconds, it resizes to a bigger one. Looks like the beginning is in a lower resolution than the rest. You can see the problem in my app: https://apps.apple.com/us/app/snippety-snippets-manager/id1530751461