Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
Nothing. I was just messing with shulker mobs. i was placing them on grass and they were teleporting around for some reason. i think thats meaningful but idk.
What actually happened was...:
Describe what happened here
The shulker mobs went together when teleporting.then they proseded to pile up shulker bullets inside them and not be able to put down there shells, because they were super high. like 3 blocks high.
Steps to Reproduce:
1.Get a lily pad or peice of grass. place them down
2. Then Spawn them on top of the lily pad/grass until 2 do go together. its easy to tell when they are together.
3. then go in survival mode and try to hit the bullets because they will go away if you hit them. if you look at the ones together they cant even shoot. and there shells will be perm. open and shulker bullets will pile up inside them.