SAP Fiori - PO Approval issue in workflow & Gateway

Hi Experts,

        I developed a custom workflow for PO approval applicaiton in Fiori.

In workflow am using the user decision step to approve/reject.For this step standard itself proving the task 'TS00008267'.

By using this task we cant able to fetch the PO related value while running the PO approval application from the URL.

Because the table 'SWW_WI2OBJ' dosent hold the values for the user deciosn task id.

Am getting the error like the 'Purchase order not found for the woritem 00000123326'

Thanks in advance

Regards,

Myilraja