Receipts post matching is not updating shipment.invc_match_status from "M" to "U" or "P"

1. Received a Shipment with ASN and for 1 item 2. After ReIM invoice Matching, it updated shipment.invc_match_status to "M" and updated shipsku as well 3. After couple of days second receipt came with same ASN but for different item, this time it has created new record in shipsku, but it still does not update invc_match_status to "U" or P" 4. Customer has to manually update the shipment.invc_match_status to "U" to match the invoice again Is this expected behaviour? ~Srini