New mobs from addons don't render properly

New entities from add-ons don't render when they have a "Locator" in their entity Json. Also, animations don't work.

I've tested this with the Minecon 2018 New Entity Samples and with a custom addon (Animacraft). If an entity has a locator, the spawn egg is black and it doesn't render, but removing the locator and restarting the world map returns the color to the egg and renders the entity.

I have no idea about what's happening with the animations, they simply don't work.