Is it a bug? Is it a technical issue?

It's more like a graphical issue...

But can someone PLEASE fix the graphics so that my long hair doesn't go THROUGH the back of my robes, down hoods, or anything with a high collar?

It's really annoying to look at and shouldn't be an issue for a game made in 2013 (let alone the option to blist someone from clicking their name in the chat box).