While having the Game in 4k (3840x2160) and turning it down to Full HD(1920x1080), the UI doesn't behave as it should. The UI looks the same, however the "clickboxes" of buttons are not on point (ex. Button is shifted to right, need to click on right side of button, where it isn't) and event some buttons couldn't be selected, in my case Exit, so i had to Alt+F4.

However after restarting the game everything works fine.