Backing Requisition Exists PO Approval Attribute not working as expected

Hello Experts,

We have defined an AutoApproval for Change Order Approvals as follows:

If Backing requisition exists = Yes

AND Requisition Line Amount = PO Line Amount

However, we've noticed that if a user creates a change order and adds a line with no reference to a PR > The Order gets autoapproved.

I've updated the rules to consider the Attribute from the Document Line as well as Document Distribution, with no luck. The rule does not identify the PO Line which does not have a Requisition. Is this expected behavior or am I missing a setup?

Any insight is appreciated!

Thank you,