Just ran into something odd here while trading with my villagers. I had two perfect librarians with paper trades as the last trade and all other trades unlocked but after one round of paper trades instead of refreshing them as per usual they replaced there enchanted book trades with worse, (more expensive), versions and made those their last trades. So is this a bug or some new feature I haven't heard about cause I'd like to know before trying for another perfect librarian.
I've not paid much attention to trading before, but in the latest snapshot, I was trading with some captured villagers and he wanted 1 book and 22 emeralds for 1 enchanted book. I traded with another one, and went back to him and the trade had changed to 1 book for 1 enchanted book and the 22 emerald part had disappeared.
Doesn't seem right to me.