I have had problems with the orientation on my iPhone 6 plus. Before I had it in landscape and when I rotated the phone to portrait, it wasn't moving back no matter what. When I hit the rotation lock, it finally went back into portrait mode. Then when I clciked off the rotation lock it automatically when into land scape again. Had to shut down the phone to fix it.
A few times it's been hard pulling down the notification center and the quick access bar.
That's happened to me on an iPad air a few times even before iOS 8.