AmEx NFC Card Not Accepting via Contactless Reader

[trynity]

When attempting to use my AmEx Platninum card for testing, which has the Contactless/NFC option, I get this error after tapping it on the reader:

I don't have any other contactless cards to try, and when just processing it via the traditional Chip method, it works fine.

Is this not supported?

[VanKalkerFarms]

I can't say I have ever had an AMEX tap card but it should work.  Only JCB cards are called out as not working with the contactless reader.

https://squareup.com/help/us/en/article/5085-accepted-cards

have you used the card successfully by tapping at any other store?

[trynity]

Yes, I recently when to Subway, which has a Verifone terminal, and Tap-To-Pay worked perectly on that.