I'll just note that I'm using revolut and some of my virtual cards on there appear to randomly be created as Visa or Mastercard. Well, couldn't pay for Claude with my Visa (no matter if virtual or physical card), but found a comment on Reddit suggesting to use Mastercard, and that worked without a hitch.

So they certainly have a problem with their flow with Visa. I wonder if the payment flow was vibecoded from scratch, never experienced that with any other site.