I have been playing warzone on pc with an xbox one controller for some time. When I hold my stick in one direction, the movement accelerates extremely and it doesn't change anything to change the target reaction curve. Maybe that's normal and I don't understand it. It can't be due to the cable or the controller. Maybe there's some setting in mw that I missed or maybe someone had the same problem and can help me. I would be very happy to receive an answer!
Maybe you have a second controller to compare it with? Play warzone yourself on ps4 😬. Hope I could help you a little. (Oh have you already reset the main settings? Maybe that will help)