I have been having a lot of trouble getting it to work consistently. I have over 450 attempts on the run and I just assumed I would get the hang of it, but it feels like a 50/50 chance of my mouse courser just moving off of the menu options on it's own or not even being on it anymore to begin with. Is there something i can do to get it every time? or is it just random?

You could try and see if navigating in the menu with the arrow keys works for you

what I always do is after loading the save to start another run, I pause and put my cursor on the save and exit along with on the yes, and if you are looking straight ahead for the most part after you crouch through the gate, it should be somewhere on the yes most of the time

but using arrow keys for quitouts also works too