1.2.3 PTZ calibration
The shift might be caused as well by drifting mechanics. Different models have several ways to handle the drifting offset. In most cases this is handled automatically by the device itself during normal operation. When the calibration is finished the device will recover its initial position. If a correction of the drifting is happening a warning message can appear.
The autocalibration will happen during the bootup process but can also be launched manually in the camera WEB GUI > System Maintenance Section.