I'm attempting to create a card-on-file customer with an iFrame API token. This works fine in the Developer Sandbox, but fails in production. I'm following these guidelines:
https://docs.clover.com/reference/createcustomer
However, in production, we're getting Error - 402 Payment Required (card_declined, Token verification failed for token clv_****).
We use the same method for obtaining a token for single-use charges, and it works fine. It only declines when we call v1/customers.
Why would this fail in production for this merchant? If you need their merchant ID, I can provide that.
Thanks!