ender dragon wheeling about more than it used to

I don't know if this is a feature or a bug, but in both creative and survival modes The ender dragon wheels around and keeps attacking me (sometimes withers too). It's rare for him to get more than 30 blocks away now. Is this how he's supposed to be? Because if so, he just got a whole lot harder- with reststance 6 on survival mode, I could tell I would have been done for in a legit fight. Screenshots coming up soon!