When I set up my Watch 4 with my Max on AT&T it came up in my devices on the AT&T website as a Samsung 7 and a Samsung 9. Thinking that odd, although the watch worked perfectly I called them. After an hour and a half and talking to 4 people they were able to change the Samsung 9 to an Apple Watch 4 on their end and cancel the Samsung 7. While they had no idea how it set up 2 accounts, one of the techs said that the numbers were likely previously linked to the 2 Samsung phones.