Minecraft (Java Edition) item duplication bug

Steps to Reproduce:

1.Load the world.

2.Place the item to be copied into the chest.

3.Then remove the items from the box.

4.Save the world.

5.Open “.../(version)/saves/ (world) “and move the level.dat out.

6.The second time the world is loaded, select the "Try to Fix" item after loading the error.

7.Put the item you want to duplicate in the chest the second time.

8.Move the original "level.dat" file back to the corresponding world and replace the new "level.dat" file.

Observed Results:

The item is duplicated in two copies, one in the chest and one in the inventory.

Expected Results:

Items should be in the box.