Shulker box block/item moves with shulkers

Shulker box items move with shulkers, as shown in the attached video.

It seems the bug only works if the shulker is in a loaded chunk.

What I expected to happen was...:
Shulker box items closed at all times in the inventory, and shulker box blocks to be closed when i'm not using them.

What actually happened was...:
Shulker boxes moved along with shulkers in game

Steps to Reproduce:
1. Spawn a shulker by any means.
2. Look at any shulker box item or block.