Items inside hoppers don't flow in order

When I want to send items to hoppers by using hoppers, they do not flow in order and you will see this in the end chest.

To reproduce the problen you just need to put items inside a locked hopper, then unlock the hooper and the items will go to the end chest as described.

Another way to reproduce the problem is by placing double trapped chest on a hopper.

Watch the video to understand the problem clearly.