Would you be able to share all of the fields on the Stock block?  The Internal 'A' field is only showing you that you have 6 products somewhere that have an 'A' status.  This field does not take into account any of the other fields you see in the Stock Section.  The screen shot you provided translate to:  6 items in A status and of those 6 items, 4 of them are allocated to detailed shortage.  The Stock Section contains several fields, and to better assist you, I would like to see all of them.  

There are Allocation inquiries, located in Stock>Inquiries>Allocations.  Specifically; Detailed Allocations.   You can search that inquiry with Site and Product to get a better understanding of what is going on with the product. 

Thank you