Ender Dragon in Overworld and Nether

Went to the End, didn't kill the dragon, died, and returned to Spawn in Overworld. Found the Ender Dragon destroying my sister's base. 

Steps to reproduce:

1. Went End City raiding with two other players.

2. Me and C3R1U5 were on XBox Ones. zBeastKeeper was on an iPad. I was hosting the world. All of us we on the most recent version (my iPad and the XBox Ones are set to automatically update). We were all on the same local network.

   1. The first time we did this it was just me and zBeastKeeper and both of us were on XBox Ones.

3. After raiding, we tossed all our stuff into an Ender Chest, jumped into the void and respawned in the Overworld. We had not killed the dragon.

Observed Results

zBeastKeeper made it back to spawn first. It happened to be where her pyramid base was built. She immediately started hearing the dragon. Although this time the health bar did not come up nor could we see the dragon. C3R1U5 was the next to reach spawn and he was able to capture some video. I could not attach it as it exceeded 10MB but I attached some screenshots. I showed up a few minutes later. All of us could hear but not see the dragon, we could be hit by her, and we saw the effects of her being there (dragons breath and destroyed blocks). Her attacks did not seem to affect any mobs in the area - just us. We could still open chests and inventory this time.

Expected Results:

Ideally the dragon wouldn't have shown up in the Overworld? But this did recreate what happened last time with the exception that we could not see the dragon nor her health bar. The first time this happened, the dragon was visible, she had a health bar, and we could not open any chests or our inventory. 

I can send video footage from both C3R1U5's perspective and mine when I arrived if needed.