If Face ID keeps telling you to move your phone up or down, it’s likely a sensor calibration issue.
- Clean the Notch: Dust or grease on the TrueDepth camera is the #1 cause.
- Reset Face ID: Go to Settings -> Face ID & Passcode -> Reset Face ID.
- Update iOS: Apple frequently releases patches for camera sensors. If software fails, a System Recovery Tool might be needed to refresh the firmware.