I think I found a solution through Microsoft's main forum actually. Has to do with Intel's display driver bugging out. Needed to be completely reinstalled and it seems to have fixed the error that...

Screen is 15.6"
I did get a screenshot of the pop-up if it helps. 238216
Not sure how to go about it if you think this is software issue

like the literal size of my screen?
I'm not sure why it wouldn't be a windows issue, because it directs me into changing my resolution. This never has happened until semi-recently so I feel like it...

For a while now games are suddenly triggering a pop up when I put them in fullscreen that says something along the lines of "Not the best resolution recommended, should be played at 1920x1080." ...