Asset tag did not come over in the interface

We have a situation where a PO was marked as asset-related, and a Tag Number was entered, but when we ran the interfaces, the asset was created without the Tag #.  This particular PO was vouchered and paid without being received/matched.  Does anyone know where the interface processes would retrieve the tag # from?  The tag # is not on the Pre_AM tables nor INTFC_PHYS_ table.

Thanks,

Andy