Hello again...
I was able to narrow it down to the following feature:
“Monitor Fading”!
When I turn this feature off, the problem is fixed.
That's a shame because I really like this feature because I have two additional monitors connected, but I don't always use them, and this feature saves power, prevents glare, and keeps the monitors from emit too mcuh heat.
So, I think it's really useful!
But now that I think about it...
I found out that when the monitor fading feature is turned off, some games (those created with Unity or Unreal Engine) run a little more smoothly, even though I always only fade out all other monitors except the one I'm playing on (obviously!).
Is there anything that can be done about this?
I don't want to always turn the function off just because I want smoother movement...
Thank you so much!