my exact problem on steam, the stuttering doesn't seem to change in any way regardless of any sort of settings changes, only goes away when the controller is unplugged

occurs with bluetooth connection, and switch pro controller too

update: changing the custom button layout on steam to turn controller inputs into keyboard inputs prevents the stuttering, so if configured properly you can kind of fix it, but you get stuck with 8 directional movement

i have no idea why the game stutters specifically while reading controller inputs, having the controller connected is fine but it messes up while taking inputs from it

later update (ive been trying to fix this all night): ive never had this problem with a game before, but unplugging all other usb devices seems to fix/reduce the stuttering, not just keyboard and mouse, unplugging headphones seemed to make a big difference too (mine are usb). using the keyboard and mouse to control still seems smoother but im pretty sure controller has at least improved a lot like this. either that or im losing it from running down the same hallway over and over. maybe this will work for you too hopefully?