Issue with Withdraw Process Button in task TS33700018

Hi Experts,

We have implemented FPM form with custom Workflow. Our requirement is if approver click on Withdrawn button, then we have to send mail to requester that "Request has been Cancelled". We used standard task TS33700018 with binding shown in below screen shot,

Next workflow step is Multiple condition on PROCSTAT. If PROCSTAT value is "WITHDRAWN" then we have to send mail to Requester that request has been withdrawn. But if Approver clicks on Withdrawn button on workitem, workflow got logically deleted & PROCSTAT became blank. In that case workflow not going forward for send mail step.

We are not able to understand why our PROCSTAT is not getting set to "WITHDRAWN" & how workflow got cancelled?

Thanks in Adv

Trip