Solution: You need to check the checkbox 'Update to all sites using this address'.
This business event "oracle.apps.ap.supplier.event" will be raised when you do following actions on suppliers/vendors
- Create Vendor
- Update Vendor
- Create Vendor Site
- Update Vendor Site
- Create Vendor Contact
- Update Vendor Contact
- Update Address Assignments
- Create Vendor
- Update Vendor
- Create Vendor Site
- Update Vendor Site
- Create Vendor Contact
- Update Vendor Contact
- Update Address Assignments