Sorry to bump this one as this exact issue is happening, but our forum has noticed this behaviour happening. If you start a video, pause it and then scroll either to newer or older posts, eventually when it loads the posts the previously paused video starts automatically.
I’ve asked some members to do some testing and all found the same issue, across various browers and even when reading read topics.
Can’t really replicate it as the issue is pretty much as described above. But if there’s anything else needed from my end please let me know.