Hi! I am currently playing on 1024x768 and with 75hz refresh rate, when I put higher resolution for example 1366x768 I feel that screen lags. I have already trying reducing some details or refresh rate to 59 and 60 but that doesn't help, also my FPS is stable at 250.
You're probably only experiencing the difference between 75Hz and 60Hz since you have stable 250 fps. It feels as if it's lagging because the screen doesn't refresh as fast as you've used to with 75Hz's.