Keep checking the Amex Application Status often the system is just a little back logged and the proccessing takes longer than the amount of time alloted so they give that message. I got something simular with my Zync card, Mine was approved a few minutes later, others have had it take a day or more.
Wallet: FNBO DISC 7.5k, , Chase Freedom 3k & Slate 3k, AMEX BCP 7.5k & AMEX Hilton Surpass 5.5k & Zync NPSL, Walmart 3.3k, CapOne AU 1.5k