Shulkers are only duplicating after death.

Shulkers are supposed to duplicate themselves after being hit by a Shulker Bullet and teleporting to a solid block if available which allows us to breed and farm Shulkers.

What's currently happening is the Shulker gets hit by the Shulker bullet, dies, and then a new Shulker takes its place without teleporting. This is preventing us from being able to breed Shulkers and expand Shulker farming.