Stop eSignature contract approval

Dear Expert,

We are using AME for blanket purchase Agreement approval , when contract term exit the system start eSignature approval after completing the primary approval hierarchy. The PO status remain pre-Approved.

We don't want to Triger the eSignature approval hierarchy . please guide how we can stop signature workflow.

Note : Below setup already checked

1. Acceptance required has null value in purchase order terms
2. In contract workbench Contract type , Signature Workflow had no value
3. if we run position hierarchy it is working fine , we are facing issue with AME