So first of all, when I spawned in the End, a lag spike hit and I fell off the edge, so I went into Creative Mode to save myself (I was having a bad day; I wasn't about to lose my stuff), but when I went back into Survival, I noticed that my armor display on the HUD was gone, and the Endermen, fall damage, nor the Ender Dragon could not hurt me; I was basically invincible. This is obviously not meant to happen.
After I killed the Ender Dragon and it spawned the End Gateway, when I used an Ender Pearl through it, it kept on teleporting me to my spawn on the Main End Island. I slayed the dragon one more time and I teleported through the new End Gateway, only to find myself back at my original spawn area in the End. Another glitch...
I flew in Creative Mode for tens of thousands of blocks, and although I found plenty of Outer End Islands, there were no End Cities to be found. After three hours of searching, I gave up.
Later on, I returned to the game and did the command /locate EndCity, and it took me to a mere 400 blocks away in the middle of nowhere, pretty close to the Main End Island itself.
Please one report per ticket, and don't forget to search as these bugs might been reported already.