Well, there's no semantic input for "year" or "currency", so there's nothing the form designer could do to stop 1Password from picking the wrong field. This does kinda get to the root of the issue, which is that 1Password has to do a lot of "cognitive" analysis of the page to find the forms it wants which is simultaneously why it does better than most autofillers, and has worse false positives than most autofillers.
I am also a happy 1Password user, and I'll happily let it prefill a complex form for me, but I've caught enough of its mistakes in the past that I will always manually double check before submitting. I could also see myself making a similar mistake as this user on this form though (since it's so simple I might not manually double check).
