Sync hz_party_sites to ap_supplier_sites_all

We are upgrading from 11.5.10.2 to 12.2.5. In 11i, we have extensively used po_vendor_sites_all.attribute2 for interfaces to/from third parties. The end user needs to be able to update attribute2 from the R12 OAF forms but the form does not reference ap_supplier_sites_all.  So, I created a DFF on hz_party_sites to make hz_party_sites.attribute2 visible and update-able to the end user. 

When I update an address in the OAF address form, it is immediately synced to ap_supplier_sites_all. However, when I update attribute2, it is NOT synced to ap_supplier_sites_all.