Hey I made a youtube tutorial if you don't wanna read the description & stuff https://www.youtube.com/watch?v=OYz7jTjaUMY

But if youtube doesn't work, then I made a description for this Enchantment duplication bug.

[How I discovered this bug]
I was on my anvil tinkering with some enchanted pickaxes and one of the pickaxes were a "Silk touch 1, Unbreaking 3 & Eff 4", the other picaxe had "Eff 4, Unbreaking 3" I was about to combine them into a pick with "silk 1, unbreak 3, eff 5" then I didn't have enough levels to do this so I exited the anvil and then for some reason, both of my pickaxes were "eff 4, unbreak 3", So I investigated this bug and sacrificed a lot of levels and materials to find how to activate this bug and this is how it gets activated.

[How to Activate the bug]
1. Pick one enchanted item that you would like to duplicate and place it on the second slot in your inventory (not hotbar)
2. Pick one enchanted item that is the same as the other item but junk enchantments.
3. Go to an anvil and click on it, Click the item on the second slot (the one you want to enchantment duplicated) and put it on the first slot in the anvil.
4. Then click the other item (the junk enchanted item) and click on it three times trying to replace the item in the anvil.
5. Exit out of the anvil and now both items should have the same enchantment.
[Note]

• If item is a tool, make sure the durability bar is full (unused)
• Item has to have the same ID with the other item

Thank you for reading this report. Hopefully you guys will be able to fix this bug with my help.

by: RedLed11