How to duplicate:

Step 1: Create a custom name for a shulker box by using an anvil or commands
Step 2: Place the shulker box down. You'll see the custom name replaces "Shulker Box"
Step 3: Log out of the world then back in. You'll see the shulker box loses the custom name.

VIDEO: https://youtu.be/SP8PiAUhluA

Notes: Haven't tested this with chests yet. I don't think this works on multiplayer.