I was just using my Curve card on the Sainsbury’s website. Some of the transactions (mostly above £50) asked for Mastercard 3D sms/email/app verification. When I clicked on email, the transaction failed immediately. When I clicked on app, and then approved the pop-up that came up on the app, the app said transaction confirmed but it failed at the merchant website.
When I tried two lower value transactions of £10 and £20 it didn’t ask for 3D verification and went through fine.
It looks like an issue with Curve’s Mastercard 3D verification, but I’m a bit confused.
I have asked the Curve helpdesk but they usually take a few days to get back.