where is the bug？

I used Onvier App to zoom in a 20x zoom camera to 20x, then zoomed out to 0x, but the camera did not return to the original 0x position (maybe it was a problem with the ms41908m driver, error accumulation, the sync move function may cause the focus motor to block the zoom motor, or the zoom motor to block the focus motor, the zoom motor clicks? How could the zoom motor exceed the travel?).