Borderless with multiple screens not confining cursor

So for a couple days now everytime I jump into a game with borderless option selected my mouse is not confined to just league and if I try to pan right it goes over to my second screen. This is fixed by going to fullscreen and back to borderless but that isn't optimal and is annoying having to do every game that I get into. Is there a fix, or is this a problem for more than just me.