[ywain]

Steam often asks for the card's CVV2 even for saved cards. I don't know what the exact criteria are, but I'm pretty sure any order over a certain amount (which a Steam Deck would definitely be) would trigger this.

[throwaway2037]

Google Pay asks me for CVV2 every single time that I want to auto-fill credit card info. Thank goodness my CVV2 is stupidly easy to remember!