Villager occupation

Villager occupations reset and force trades to change.

I had a villager boxed up so I don't lose him (and to make sure it's the same one), and his trade changed from 36 emeralds > mending to 5 emeralds > bookshelf.

I was in the area (<10 blocks away). Didn't buy from him yet (new mechanic that trades change spontaneously?).