When a shulker is applied the tag invulnerability, it still receives damage. Either I have typed in the wrong command or the shulker is supposed to be invulnerable to any damage.
Steps to reproduce:
1. Summon a Shulker.
2. Apply the tag Invulnerable.
3.Damage the shulker.
Players in creative are supposed to be able to hurt invulnerable mobs.