Issue in release of PO when triggered through Workflow using BAPI_PO_RELEASE

Hello All

I have a workflow which is triggered when there is a Down payment in the PO and at the end when release strategy and all is in place it should release the PO. I am using BAPI_PO_RESET_RELEASE and BAPI_PO_RELEASE when I am testing the BAPI stand alone in the method it changes my Release indicator from Blocked to unblock in ME29N but when the same thing happens through workflow the release indicator doesn't change. Kindly help me for the same. I am attaching the code I have written in the method.

Thanks

Aditi