PO history is not updating in SRM EC PO

Hi

We have implemented SRM 7.2 EC scenarios.

Againt the PO in ECC we generate the Down payment request and Down payment document. It update in as PO history within ECC PO. But Related documents tab with SRM  PO we can't see down payment request number or document as follow on document.

Where if we generate GR/Invoice/Sub Debit/Sub credit/GR-IR maintenance document within ECC, we can see as follow on document within related tab of SRM PO.

regards

Dayal