Update of GR-based invoice verification indicator

Hello,

We have a schedule agreement, where we have not activate the Indicator GR-Based Invoice Verification (zone EKPO-WEBRE).

Some Goods have already Recept.

The buyer have updated the net price on the Schedule Agreement, after the good receipt.

When we post INVOICE in MIRO, SAP takes the actuel price and not the the price of Goods Receipt.

Is there any way to activate the Indicator GR-Based Invoice Verification, after Goods receipt,

and posted INVOICE with the Good receipt price

Thanks in advance for your help. (sorry for my poor english)