Updating the authorization status in PO Headers using a custom program

Hello Experts

We wrote a custom progra to update retention % and also updating the authorization status to Requires Reapproval, we ran the program and system updated the retention % and the status is also showing as Requires Reapproval from front end and backend however when the user is submitting for approval by clicking on Approval options (this is our process) getting an error message as below

You cannot define approval options for documents that are already approved.

We are in R12.1.2

Please advise

Regards

Dilip