While adding an Amex card to the sandbox tester account, it is showing an error as "This card cannot be used".
The card initially shows as added but when you look at the device account number it says "Activating..." indefinitely and is never activated but MC, VISA cards are added successfully.
Following probable solutions have been tried:
The card initially shows as added but when you look at the device account number it says "Activating..." indefinitely and is never activated but MC, VISA cards are added successfully.
Following probable solutions have been tried:
Setting device location to the US
Creating a new sandbox account and tried adding but no luck.