Have you tried tapping the cards and using them anyway?
A recent-ish update in Pathfinder changed things from: "pre-roll to see if you can use weapons or spells" to "only roll to use weapons or spells if you try to use one." Net effect is the same (i.e. you still need to pass the roll), but the game only make characters roll if they attempt to use a prohibited card.
I'll give it a shot the next time it comes up, thanks!