Problems with multiple display

the game has 2 problems with multiple display that is a little complicated to explain so bare with me.

I have 2 displays, one connected to motherboard (display 1) and one connected to my VGA (display 2).

in windows display settings if I choose display 1 as main display, and in DST choose display 2, the problem is DST still gets scaling settings from display 1, so if I change display 2 scaling setting to %125 in windows display settings, the game will be is a bad size, so the scale setting for display 1 and display 2 should be the same (both 100% or both 125%) for the game to be sized correctly, this problem will not happen if I choose display 2 as main display in windows setting, which I don't want to do for other reasons.

the other problem is when I choose display 1 as my main display the game is laggy, and it will fix if I choose display 2 as main display. my graphic card and app are updated and working (gtx 1650 4g). 

I have not this problem with other games.