PO Amount exceeded by voucher - what Match Rule is needed?

We are on Image 40, PT 8.59.3

We are testing a process to reduce a PO by Change Order which adds a second line for a negative amount.

When a voucher is created, using Copy from PO, and only the first line is copied, the PO line amount is greater than the PO Total. The Matching process did not create an exception. What Match Rule is needed to prevent voucher line amount from exceeding PO Total Amount?

See screenshots for more details.

Thank you,

Andrea