Not talking about keys to access Ubers or anything, but just good old standard keys to unlock locked chests.
I try to keep a stack in my inventory because I’m greedy and I always think the next chest will drop the best gear/runes ever (especially in LK runs <_<), but I’ve noticed that I always have 12 keys. I specifically opened a locked chest and checked my inventory right afterwards: still 12 keys.
Is this a bug or working as intended?