Hello Guys,
WHat I am going to tell worked for me, you guys can try and check as well
1. Play a video in picture in picture mode.
2. Lock the iPad (the video will pause)
3. Press the home button, do not unlock yet
4. Play the video while you are the lock screen.
5. Now your video should loop by itself.
Try it with a small video file first.
Thanks and have fun guys
Muhammad