Failed payment due to 3D Secure error
You have initiated a payment, which sometimes might seemingly look successful but still received an email from us indicating that the payment was not, this could be as a result of a 3-D Secure error. 3-D Secure is a protocol designed to be an additional security layer for online credit and debit card transactions.
When our payment provider (Stripe) detects that this security check has not been completed, it will abort the transaction hence, why we notify you to retry the payment to ensure that all the security checks are completed. You can learn more about 3-D Secure on Wikipedia.