Wakelock for 2D (standard/normal) tours

Hi,

I read somewhere that in order to keep handheld devices awake, a
video has to run in loops in the tour. So I made a transparent
(alpha=0) 2 pixels by 2 pixels (so 4 pixels total) video file
(defined as layer) run in loops. It works fine on a smartphone
running on Android 7, however it doesn’t work with the most recent
Android version.

I therefore believe that I don’t do it correctly, should I make my
video file larger (more pixels), if yes how many? Or is there a
better way to achieve this goal?

Thanks!