Why isn't my view in the game following my head movement?

This is most likely due to a problem with the device tracker. Since your display is working, the wires connecting to the tracker board should be fine, so the problem is the tracker board itself.

I suggest trying to re-calibrate the device first since faulty calibration could cause the tracker to move in the wrong direction. To learn how to calibrate your device, click here.

If your problem still persists after calibrating, you should replace the entire tracker board itself - refer to the Oculus Tracker V2 Board Replacement guide.