Apple Pay Issue - Shipping Address

I am trying to use Apple Pay on Indiegogo.com via Safari on iOS 11 and Safari Version 10.1.2 (12603.3.8) on MacOS. I continue to get a red exclamation point stating "Shipping Address". I have tried both of the cards I have authenticated in Apple Pay but still get the same "Shipping Address" red exclamation point error.

I have also gone in and deleted and reentered all of my Shipping contact information.

Is this an issue with this site or a Apple Pay bug?