I think they have Visa options as well- I have Revolut Mastercard but my friend was handed a Visa card during one of their events. It might be worth checking this thread, as I faced the same issue when I was in South Korea (Monzo in South Korea 🇰🇷 [Discussion]). I think Rika mentioned here that it was an issue with the chip positioning, but that should be resolved in the recent batch of cards.