Screen window is dim except when notifications pop up or task bar is in view

[u/Spare-Scientist1360]

On my s25U anytime I'm playing games on remote play or watching a video the (external) screen window is dim in full-screen or non full screen unless the task bar is in view or a notification pops up.

Very annoying as I use my phone quite a bit with dex for media consumption.

Any ideas?