Repro Steps
The ShippingAddresses table is populated with ReturnTo address information when ConnectionManager detects a lender has shipped material. In the event that a lender undo's shipped and a new lender supplies the material, the ShippingAddresses info on the borrowing side will contain the wrong ReturnTo address information since it is not updated in the event of a lender conflict.

1.) UCW request a book from Lender-A
2.) Lender-A updates shipped but recalls book right away and perhaps never actually ships it
3.) UCW rerequests and is filled by Lender-B, which updates as shipped as expected.
4.) UCW checks in on their end once item received.

The Check in from lending library form should update the ShippingAddresses information with the current ReturnTo information after associating with a lender