The crafting help unsuccessfully tries to fill up incomplete stacks with the same item but a different sub type when you shift click a recipe which allows multiple or any sub types, such as creating a wooden button from any type of plank. This results in the items of the different sub type being deleted.
- Place two kind of planks in your inventory, but make sure the first stack is smaller than the maximum stack size
- Make sure you have the wooden button recipe unlocked
- Open your inventory or a crafting table
- Shift click the button recipe
→ The spruce wood planks stack is reduced to 32 items