End dimension terrain generates overtop the obsidian pillars

End dimension generates terrain overtop the obsidian pillars and the dragon flies primarily underground.

What I expected to happen was...:
Endstone generation stops at the base of the obsidian towers

What actually happened was...:
End stone reaches height of 250+, completely encasing the obsidian towers.

Dragon flies around under ground and is unable to be killed reasonably

Steps to Reproduce:
1. Load into the end
2. Observe