I’m not sure, which is the exact reason, but a few days ago I was playing around a bit, and I’ve noticed a behavior for postrational headtracking equally strange in other games as well and I never finish finding out the cause.
I move my head looking down but without taking anything off my back in the chair, however the view tilts a lot towards the ground.
Sometimes I have tried to mitigate a bit this, reducing positional force tracking slightly, in order to slow it down minimally.
Why does this happen sitting in the chair?
that is, the actual movement of gaze downwards does not coincide with the movement made within the virtual world.