Version: 1.12-0.2.0.21
Forge version: 14.23.5.2854
Other mods: JEI version 4.15.0.296

Crafting items into a filing folder deletes items that you add into the same stack of the grid after the first stack.

How to reproduce:

1. Place an empty filing folder in any crafting grid
2. Place any other item next to it, e.g. one Sea Lantern
3. Add another item of the same type to the stack (i.e. grid now contains stack of 2 Sea Lanterns)
4. Hover over the output filing folder
   ⚠️ it still says "1 Sea Lantern"
5. Take out the filled filing folder
   ❌ the whole Sea Lantern stack in the grid is consumed, but only one is in the filing folder