Added a small cursor clamp so that now it's harder to click out of the window mid gameplay. It is not perfect because I can't do it on OS level so if you flick harder it falls out between frames. So as long as you don't swing the mouse while spamming the mouse then things should be fine. Of course what can also happen is that you hit frame perfect or hit even a good enough speed to make it fall out.
I might need to hunt down a plugin or hell write one myself. I'm on it but for now this is the best fix I have. All this gets turned off if you open the inventory so you can still click out of the game.
TL;DR
I added a bandaid fix on the cursor falling out of the window mid fight, now im trying to make it less ass.