Item Code Renaming After Warehouse receipt

Hi Guys 

User encountered an error NAV complaining item does not exist and i found out that warehouse receipt has been done from the and when a user tries to perform purchase invoice from the receipt, NAV repond by returning Item xxx. does not exist and after the warehouse receipt the item code has been changed by a whs user.

my question why is that allowed to be performed on the fist place by NAV is it normal situation or a bug

NAV 2017 Version