I have to wonder if somehow the cookies on your computer from your Costco booking session were used by the AAA session and the DISNEY site was confused and thought you were still coming into their website via Costco.
If the AAA website (which I have not used) links into the Disney site this is most likely what is going on. Let us know if you ever get an answer to this...
If the AAA website (which I have not used) links into the Disney site this is most likely what is going on. Let us know if you ever get an answer to this...