Weird Screen Glitch

[Shinikami1]

I've started playing this after taking a break for a few years, and my screen has a strange glitch!
It's solid in the middle where the monitor is, but has lines to show where the monitor flicks up and down, its noticeable when moving as the lines divide the posters or amatronics in half when moving the screen!
It's really confusing to see

[Miss Rin]

it has something to do with V-Sync

[Shinikami1]

Any idea how I can fix it?

[robo_cob2]

never seen it before