Is it quite possible that the sleep dimensional hopping could have been caused by the stress Star was putting on with her efforts in trying to be a better princess?
Since the first dreams we saw her having were about flying around freely and doing fun stuff, I think that’s a very safe assumption to make. An unconscious search for freedom opposed to the bundle of responsibilities Star’s life suddenly became. What we still don’t know if that’s all what it amounted to, Star “wanting to be called” to a paradise where she could have forgotten about anything, living in complete relax and harmony (but at what cost!), or if there was more to it, something bigger and more closely related to magic.