This unit uses a linear motor to drive the lens.
When the linear motor is not powered (*), the lens group is not held in a fixed position. If the unit is shaken, the lens group may move and produce a sound. However, this is not a malfunction.
In addition, even if the internal lens group moves due to vibration during transport, etc., this will not affect the performance, etc.
* When the camera is turned off or when the unit is not attached to the camera