While playing the very first part of Act I where you fight the spirits and come to a guard who is in the middle of a triangle and looks possessed (whom you're supposed to click on and talk to), I went to try and click on him but it wouldn't let me. I moved my cursor around a little and found I could click on him when my cursor was North-West of him or upper left of him. I then found it was that way for anything I tried to click on, even menu icons.

This didn't happen until after I went afk from the game and left it running. My computer screen went dark as normal when I'm away from it but everything was still running in the background and I haven't had this issue with any other game so I highly doubt it is a computer setting on my side.