Hopper lock fails during split screen multiplayer

Only while playing splitscreen multiplayer, a locked hopper is able to pull an item from chest above. Steps to replicate:

1. place a hopper beneath a chest

2. Lock the hopper by redstone (i used a redstone torch)

3. Place one item in the chest. it should remain there.

4. Have a second player join the world via splitscreen

5. Player 1 and player 2 leave the area, quit and rejoin

6. Either player returns to the chest

7. Sometimes, the item will have migrated to the hopper for no reason. Not easy to replicate but with hours of testing I was able to replicate many times.

This makes copper golem item filters impossible.

Standard hopper filters seem to work without issue. This makes me think it is the relationship of chest and hopper that’s the issue, rather than the hopper alone. (A locked hopper never pulls from a hopper above)