We are currently aware that our card processor is experiencing intermittent failures for 3D Secure Challenges for Card Transactions. They are currently working towards a resolve on this matter and we continue to liaise with them to aid in their resolution.
At present any card transactions which are verified using 3D Secure may intermittently return an unsuccessful response - this wouldn't necessarily entail issue with the underlying card.
We continue to monitor this issue and will share any updates as, and when, these become available.
Please accept our apologies for any inconvenience caused.