The scores you received from EXP are known as FACOs because they aren't true scores. I believe there's no way to get it other than from a lender or through a certain CU. Anywho, what they sent you is your true score, but it's not the only thing Amex uses in their decision. They have their own internal scoring system, and your score plays a part in it.

The only true fico scores you can get are TU and EQ and you can pull them from this website.

Hope that clears up some confusion.