PO match to AP invoice

Hi,

I'm in 12.1.3 and I have a situation.

I have 3 supplier invoices that are matched to the same PO.

PO has 1 line with total quantity 12 and each invoice is for 1 unit.

The 3 supplier invoices were matched to the po and now are in Needs re validation  with Hold Qty Rec. Because until now there were no receipts at all.

So far so good.

The situation is: now there is one receipts done for 1 unit

When try to validate invoice number 1, it doesn't validate.

Then a new receipt is done.

So, now there are 2 units receipts and the 3 invoices remains on hold.