the supplier sites assigned to multiple business units for the supplier is not importing

the supplier sites assigned to multiple business units for the supplier is not importing from spread sheet with exception "The supplier site isn't valid. It must be an active purchasing or sourcing-only site of the supplier and assigned to the requisitioning BU. If the same site name exists across multiple procurement business units, then either the requisitioning BU supplier site assignment must be unique, or there must be an agreement to determine the supplier and supplier site." where as the supplier site is unique, active and assigned correctly the multiple BUs. the PDF file is attached for reference.