Issue while posting physical inventory document

Hi Team,

While posting a physical inventory document system is giving error message saying that

HU exists at another point in the warehouse. Clear the HU first

Message no. /SCWM/GM751

here is my scenario: As per the system bin is empty, while doing physical inventory we found and counted one HU in the same bin. while posting the same physical inventory document we are getting the above error message. as per the system this HU available in some other bin.

could you please let us know is there any process which i am missing before posting the PI document.

while posting the PI document is it not possible automatically HU get move from one bin to other bin?

Thanks

Mastan