Whenever selecting the part to the left where all the villager trades are shown, it will look for if you have a book in your inventory but upon selecting it to perform the trade, it will complete the trade and consume the emeralds and not the book.
Comments 2
Cleaning up old tickets: This ticket has not been updated recently (~1 year+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
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Also happens on Xbox. I made a trade for a mending book from a villager and while it took the emeralds I still had the book in my inventory