Put the summary of the bug you're having here

What I expected to happen was...:
That we would ender the end to take on battle with the enderdragon

What actually happened was...:
The enderdragon was frozen in the sky, Totally non interactive.

Steps to Reproduce:
1. used the command /spawn EnderDragon
2. Now have two enderdragons one in the sky one on the ground...
3. .Thought I would try on the upside world
4. Now I have three totally un interative enderdragons.

All seemed well before the update. 1.9 Realms on survival Easy mode. Since update not possible to kill enderdragon so therefore not possible to obtain Elytra or see the end.

Children sad ..Have tried numerous inventive ways to destroy them. Please help. Changing game mode to creative doesn't work.