I've been trying to recreate this bug but it's not the only time it's happened.

Shulker boxes don't seem to be remembering items.

Timeline of events:

1. On a shulker-shell/elytra raid in the end-dimension.
2. Couldn't use an ender-pearl in a gate to get back to the main island.
3. Decided to suicide after putting all my things in shulker boxes, and putting them in an ender-chest.
4. Dove into the void.
5. Died, respawned back at base.
6. Items I stashed not in the shulker boxes I put in the ender chest.
7. Tried closing the game and re-opening, to see if that would fix it, but nothing.

Also of note, when I respawned, none of the armour stands were visible, none of my wolves were visible, and neither were any of the item-frames, or chickens in a farm I built. (I could hear the wolves and the chickens, but they weren't appearing.)

What I expected to happen was...:
Shulker boxes should have stored the items I put in there.

What actually happened was...:
Shulker boxes didn't remember the items.

Steps to Reproduce:
1. Unsure what to do to recreate this.