I entered the End Portal in survival and broke all the Nether Crystals like you normally would. After I broke all of them the dragon came down and stayed above the portal for a bit like it normally does and I started attacking it, after it had flown away, it just continued to circle and never came back down or fired a fireball (or whatever you call it).

Here is a video to show you what I mean: https://youtu.be/nXfiRpsyrT0