Dead by Daylight definitely needs to be updated. The sensitivity is absolutely inaccurate (at least for me). If I convert my CS:GO sensitivity to DbD, I would have to go down to 260 DPI (look sens -25) , but that is way too slow - I tried it. I have in-game sensitivity at 25% at 400 DPI and that feels much more familiar (so a huge gap from the calculated -20%).

Link to Calculator settings: https://www.mouse-sensitivity.com/?share=eea195f127eb408f0279b0e3d9b2d5d5

At some point they have enabled smoothing in this game, so you get a lot of negative acceleration with high polling rates. I have updated the game info with instructions on how to disable it, this should solve your problems.