Okay, so you figured out what causes the mouse issue. When you fix that, you're still having the light issue? Just wanna be sure I'm getting that right.
Viewing post in Looking for help or tips?
There should be a tick box in the visuals somewhere to switch it from normal fullscreen to borderless. Now that you mention it, there may not be a windowed mode, and I remembered that wrong. I apologize for that. If you already tried the tick box, though, I would say make sure your resolution is set correctly. Or -- in games that have done this to me before -- try resetting from fullscreen to borderless, or the other way around and see if that improves at all.