I don't know if anyone has seen this glitch before, but I was on my mount, and then it flew off without me. I was still floating there, but my mount just, kind of road off into the distance. Its FUNNY, do NOT get me wrong, but It was weird just sitting there floating.
I have the Hawk Mount, and it also glitches, but in a different way then yours does. Since it flies very high, the mount goes down to the normal height of a mount, while I'm in the sky. Lol. Taking it off it and equipping it again fixes it though.