Mouse sensitivity problem

[Nox Deleo]

+1 with this problem (4080x768 Eyefinity). Likewise previous games worked fine. I'd love to suck it up and play with one screen, but extra immersion is really worth it in this game. Made the other games that much scarier. I'm sure I can come up with a hack for it, but I'd really appreciate if this could be fixed with a ratio in the settings, or one set automatically from aspect ratio, or whatever you can do. Thanks.

Edit: I did notice it was fine on the pause menu, just not in game.