So on top of all the OTHER villager bugs I had to deal with to even get this mending villager in the first place-

My current status in the provided gif:

• i have hero of the village effect
• i successfully traded the paper trade until the paper trade got locked (and the villager leveled up)
• i successfully obtained a single mending book
• after getting one mending book, the cost of traded from 6 emeralds to 4 emeralds

What's wrong:
instead of giving me the mending book, it gives me a ghost book. It's not shown in the gif, but if i shift click the book instead of simply trying to pick it up with my cursor, a ghost book is given to me for a split second before disappearing and giving me my emeralds/books back

please fix villagers. it's a shame that mojang has pushed out a full release for 1.14 despite villagers (the main focus of the update) being so buggy that they're literally unusable.