Can't Summon Ender Dragon 1.9

What I expected to happen was...:
Summon the Ender Dragon

What actually happened was...:
In 1 world I can totally summon him with ender crystals, in the other world that I played on snapshot nothing happens when I put the crystals down.

Steps to Reproduce:
1. I put the crystals in the exact same place, in the exact copy of the map, but played previously in snap
2. There was a moment that I accidentaly loaded the world on 1.8 after using it in snapshots near 1.9. Is it fixable by anything I can do?
3.video link https://youtu.be/ZpSb3OXpDnc