Dead zone for analogue stick movement is too small
A brief explanation of dead zone here: https://itstillworks.com/12629709/what-is-a-dead-zone-in-an-fps
OpenMW dead zone is so small that it exhibits "ghosting" on the 360 controller I use to test, drifting the camera or the player character without any input. Other games such as Skyrim have a more generous deadzone where these problems do not occur, so you do not need a brand new controller to play.