Issue with invoice matching

After our recent upgrade to 12.2.9 the Payables department has reported a change in the way Oracle is handling invoice matching. Here is a sample scenario:

We have a PO with a qty of 1000 for product X. We get 3 receipts against this PO of 250, 500, and 100. We get three invoices, one for 250, one for 500 and one for 250. All three go on hold. Payables clerk removes the hold and manually match the first 2 invoices (for 250 and 500) because we have receipts that will cover the invoiced amount. When they run the validation process Oracle now also validates the third invoice even though the receipts are still 150 short of covering it.