Some headaches since adding a new 4k monitor

[shankly1985]

So I was using before my main monitors 1440p 144hz with a second monitor 1080p 120hz.
I just got a new 4k 160hz monitor and put my 1440p one to the side for second monitor.

Within Windows I have set the 4k monitor as the main display. But when I opening some games they keep locking to the 1440p monitor and flickering in and out until I can finally set them to the 4K monitor.
Opening new games work fine, as anyone notice issues like this before?

 

[sy-core]

I'm sure in some games they have an in game option for what monitor to use, i can think of warzone for this, but it may be that the options under graphics or video need changing in game.