Consumer (customerType=02) is created with no address data. This consumer is used to create order in COM. COM asks user to add address. User adds the address, moves to add item screen and then to Change Fulfillment Options screen. On this screen user sees duplicate/redundant address displayed under "Ship To Address" dropdown.
Why does COM show duplicate addresses?
On 'Add Item' screen when user adds an address, COM calls manageCustomer API and createOrder API. Both these APIs create two different records in yfs_person_info table.
createOrder API creates record in yfs_person_info table with address entered by user on customer identification screen
manageCustomer API creates record in yfs_person_info table with address entered by user on customer identification screen and other data present on customer like email id, title, first name, last name, etc.
On Change Fulfillment Options screen, in "Ship To Address" dropdown. COM shows only few attributes like AddressLine1, AddressLine2, City, ZipCode and Country.
Both, Address created by createOrder API and and that by manageCustomer API, have same AddressLine1, AddressLine2, City, ZipCode and Country. Hence, both the addresses which appears on screen look like duplicates as the visible attributes are the same.