The Cage Cursor option breaks if you click the Window that the game runs in, rather than inside the game window itself. I don't know if that can be fixed

 

I suppose the game can be run in a borderless window.

what does caged cursor do? I'm unfamiliar with that term and I don't recall it ever being in a game I've played?

It forces the mouse cursor to remain inside of the game window. PoE lets you scroll the map by hitting the edge of the game window. But if the game window is either not full screen, or you have a second monitor it'll just move the mouse outside of the game.

 

Caged Cursor prevents that.