I've been stuck on the 3rd riddle too. It says I did it correctly but I've received nothing and can't reenter the answer (I know I got it right too, I've read that book a few times lol).

Same, but with the eight riddle. We all know the answer to "whats in my pocket" but it doesnt work.

I play Desktop on mac via steam

I'm playing on PC via steam, and I'm having issues as well. I was able to redeem the first two codes without issue. But the third riddle never gave me my reward, although the message in the store indicates it redeemed successfully. When I try to redeem it again, the store claims that I've already redeemed it. I've tried relaunching the game and reattempting to use the code. But that doesn't work either