Unable to attach a standard invoice to a credit invoice under credited invoice field in Accounts Pay

Dear Experts,

We have recently applied RPC 3 (Recommended patch collection) in our instance (Oracle R12 , 12.1.3 Application, database version: 12.1.0.3).

Since then we are not able to attach the standard invoice to our credit invoice (Under credited invoice column as we earlier did)

When we click on the quick invoice tick and attach the standard invoice to the credit note it settles the total amount of the standard invoice not just the credit invoice amount.

Appreciate if you could provide us an answer?

Thanks