In R12(12.1.3) when processing payments the Supplier Site address does not show on the LOV or Oracle

We are in Oracle R12(12.1.3) release and having issue in Payable when creating Quick Payment or batch payment processing.

Basically when we enter the Supplier name or number their Supplier site by default does not populated as it was in 11i. We have to pick the Supplier site from LOV. This is not right

as we have most of our supplier with more than 1 active Site. Here is my questions:

   1- Why the vendor SITE does not automatically populated If we are trying to generate a payment for their open AP Invoices?

   2- Why the supplier address does not show on the AP Payment sceern. It only shows their Supplier Site code, Payee Country, Active & Payment Function field. It does NOT show their address like, city, state, country...