THIN WHITE AREA appears when moving cursor to edges of screen

Currently running macOS Ventura 13.4 on a 2021 M1 iMac.

Thin white area appears when placing my cursor on the left-most or right-most side of the screen.

And no, I'm not talking about the note pop-up at the bottom right of the screen.

It's more towards the middle of the left and right.

How do you turn this off? And what's the point of this?

During a game, my cursor gets completely stuck on one side of the screen and I have to shake my mouse to release it from the edge. And sometimes the cursor completely disappears.

Thank you :)