Unable to change Contract Agreement on duplicate PO line

Summary:

We have a requirement to change Contract Agreement on many existing POs. I am trying with VB excel plugin. I was able to duplicate PO lines, but i am unable to change agreement. Tried by providing only new contract agreement number and along with agreement id. But no luck. Please advice.

I am able to change contract agreement from UI and process it. But getting error with VB excel plugin. Attached excel used for this.

Content (please ensure you mask any confidential information):

Error: You can only update the SourceAgreementId attribute for incomplete purchase orders or purchase orders withdrawn or rejected during the approval process. (PO-2055701) (PO:::PO_REST_CHG_AGR_INVALID)