This is has happened to me repeatedly. I have my correct and current passport information stored in my SkyMiles profile under International Travel Info section, along with my KTN/GE number. Every time I check-in for an international flight, it makes me enter my passport number.

The International Travel Info section description indicate the passport info would be used during check-in to simplify things but it doesn't appear to work for me.

Anyone know how to fix this issue?