When entering the end and fighting the dragon, whenever he shot his big ball at me, it would land 10 blocks away from me but some invisible force would take 2 of my hearts every quarter of a second, regardless of the immensely powerful armor I was wearing, or how fast I tried to run away. If this is the actual correct style of attack, I don't know what to say. I tried 20 different times to beat him on easy mode, didn't work.
Steps to recreate:
1. Enter the end, survival mode, honest gameplay
2. walk within range of dragon to start attacks
3. get vaporized in 1 second even with full diamond armor

Please note that I was a beta tester previously before unenrolling from beta and uninstalling and reinstalling the game. I have found no other bugs from the corresponding world/game i have played in.