It happens to me on voyager. OP didn’t mention but I think they’re specifically referring to videos with vertical height larger than the screen. The video starts playing as you scroll and when the video is playing, I assume any touch gesture on the video is interpreted as video controls so you’re essentially stuck there without being able to scroll. Only way out is to kill the app and relaunch. Maybe it’s specific to iOS. It’s happening to me on iPhone 13 mini.