Huge performance drop in "Settings" menu with Windowed Mode

[Aspect]

Hello everyone. I have a pretty weird issue here. When im playing in windowed mode, game itself works great, but when im going in ESC menu -> settings it drops fps down to 2-5 and everything, like button highlighting or screen scrolling in keybind menu lags like crazy, game even starts blink black in OBS if im capturing it. This even happens when game not loaded and im only at the home screen, going in setting from there. And yes, with game loaded it lags way harder, then if im entering settings without it.

Also to mention, when i enter settings menu i can see a "System" process in task manager suddenly starts to use 30-40% of gpu and same for cpu, sometimes spiking even more, together with game process eating almost all resources. It stops doing that when i quit from setting (thus getting back my game performance) or when i lose focus on games window (so problem goes back when i focus it back). This process uses only 1-4% at the same time if im doing it in fullscreen.

So question is, is there any way to fix this, 'cause its annoying as hell. Any ideas?

[Aspect]

Oh! I just saw info on home page about unstable branch and performance fixes and decided to give it a try, even though im not a mac user, and it looks like this fixed my issue, i double checked it with going back and forth to release version and beta again, all works great, with zero problems. So for all people with different strange lags in 1.0 release i recommend at least give a try for beta brunch update, it may help