Reassigned AP Invoice Approval Goes Back to the Requester's Hierarchy

Summary:

We have AP Invoice Approval rules - Approval Routing as "Job Level Hierarchy" with Starting Approver "Manager of Invoice Header Requester".
When we reassigned an approval, it goes back to the original requester's hierarchy after the reassigned approver approves the invoice instead of following reassigned approver's hierarchy.

Expected Behavior: A1 Reassigned to B1 then it goes to B2 > B3 > B4
Current Behavior: A1 Reassigned to B1 then it goes to A2 > A3 > A4

Do you know why it returns back to the requester's heirarchy?

Version (include the version you are using, if applicable): 26A (11.13.26.01.0)