Adding items to a container at the same time as a hopper sometimes leaves an item behind in the player’s inventory

Steps to Reproduce:

1. Place a double chest

2. Place a hopper on top of it

3. Lock the hopper using a lever

4. Place a double chest on top of the hopper

5. Fill the top chest with an item, and then fill your inventory with the same item

6. Unlock the hopper

7. Quick move the items in your inventory into the bottom chest

Observed Results:

A single item is sometimes left behind in the player’s inventory.

Expected Results:

No items should be left behind. They should all be transferred to the chest.

Video: