Cannot verify Mastercard when trying to add it to Apple Wallet

I'm trying to add a virtual Mastercard to my Apple Wallet. I typed in the card number and expiration date, and now it is waiting for verification. However, when I tap the verify button, the pop-up immediately closes again by itself, and it's not possible to click the "next" button ("næste"). I can't do anything from my bank app either. I have of course closed and opened settings, restarted my phone, etc.

Wallet and Apple Pay works with my Visa cards, which I also have physically. But I've had virtual Mastercards added to my Wallet before, that worked just fine, however that was another bank.

Can someone please help me figure out how I can use my mastercard with Apple Pay? Thanks!