I tried forum search, but nothing came up.

I booked a ticket (with EY) months ago, then had to rebook recently (with a different card) and shortly after got this email:

"We were unable to authenticate the payment details of your booking; therefore your ticket has been suspended on security grounds."

The booking reference on their website still shows as "confirmed" though.

Both payments cleared.

They said I'd have to bring the card with me when checking in for the flight. But which one? Due to the timing of the suspension, I suspect there was a problem with the verification of the second card (used for rebooking fee), not for the first card (used for initial booking).

What happens if I do not show up to the flight? Does this situation give me the opportunity to no-show without penalty?