My 2011 also has U in that position. The only reference to Korea-built Santa Fe's being built at Asan is on Wikipedia, not known for accuracy, but I can't find any references at all to Santa Fe being built at Ulsan.
Does it matter - your Santa Fe is Korea-built, not US-built - the fact that you have a VIN means it's on a ship already.
The Hyundai ships do stop at an awful lot of places on the way, to offload some of their cars, so may take 2-3 times as long as a direct voyage from Korea to Australia.
I was desperate for my Santa Fe, having written my Subaru Outback off, but still had to wait from late October till late January - I managed to pick up the ship in the Indian Ocean using AIS and tracked it every day but with Hyundai factories in India and Eastern Europe it made lengthy stops to take on their output and then seemed to stop at every port in the Mediterranean before going down the North African coast, up to Antwerp, arriving in London just before the Christmas shutdown!