Mount bug

When I am using my flying or my running mounts (I have tried using different mounts and it still remains) sometimes I am moved back to the place I was before. This hapens like 5-6 times and after that I can continue to my way of going. This was happening before, but it wasn't occuring often. In the past few days it happens every 3-4 minutes. It makes the game hard to play. Is there a way of fixing it?

That means that you are lagging.

That's not a bug, it's called "rubberbanding" and is directly correlated to your bandwith/ISP connection.