Yep, Ralf says headtracking acts as a simulated 2nd mouse, which BF1 does not seem to like. I’ve discovered this same problem in BFV as well, sadly.
Until a proper solution is found, best alternative is use immersive/cinema mode zoomed in very close, which can give you a few degrees of “freelook” around the screen. Instead of disabling headtracking, just turn the sensitivity slider down to zero on the main page.
Or use a controller instead. But that’s not how I game :)