When I was trading with my librarian villagers, I clicked on the enchanted book I wanted in my survival world (which the screenshots below are in my creative world, unrelated) but the trade in the trading menu on the right of the screen, the item wouldn't show up or would give me another trade of theirs that I didn't click on. No matter how much I clicked on the trade I wanted, it would either not give it to me entirely, give me another trade I didn't want or nothing would show up in the trading menu. I'm very confused by this, because I've shut down my computer, quit minecraft many times, changed worlds, changed the verison, have the correct amount of emeralds but it still won't go away. I've provided screenshots to explain what's happening.
-Screenshot 2021-02-03 03.33.24.png
this shows that it works fine on my farmer villagers and i can pick up the item i selected and trade the emeralds for the bread
-Screenshot 2021-02-03 03.32.49.png
when i click on the paper to emerald trade box (and you can see i have it clicked because there's a box around it in white) the emeralds or paper aka the item wont even show up
-Screenshot 2021-02-03 03.32.44.png
i'm clicked on the enchanted book trade but nothing even shows up in the trading menu (i have 3 emeralds but it still doesnt work with 64 emeralds, way more than i need for the trade)
The librarian wants paper from you to give you emeralds.
The librarian also wants a book from you and enough emeralds from you for the trade to succeed.
Essentially,
everything to the left of the arrow, you give to the villager (input),
everything to the right of the arrow, the villager will give you in return for your input