Android box issue

hello.
Come across a recent problem when using my android tv box to watch videos in full screen.
The issue is that android places a blue highlighted overlay over the full screen video that I cannot get rid of.
Some apps has a work around where I go into mouse mode, click the video then go off Mouse mode and adjust the volume however this only works every now and then and has become a massive hinderance when watching videos.
The os is the tv version so doesn’t have a actual android rom so settings are not much help. Any idea how to disable this?
It is a schision android 9.0 tv box, think it is the ai two model but cannot find out for sure online after looking. It has the rk3228 chip if that helps anyone with any suggestions.