I have the same problem in the 2nd quarter top-down on the left side, about half a centimeter from the side. Being a curved display, high pressure on the margins of the display is the cause of that problem. Maybe it is from the pocket (you move, you bend and you put presssure on the screen). If you press hard on the edges, you will see the screen turning from white to gray. That does not happen if you press hard towards the center of the screen. This gives me the impression that there is no body frame on the sides for the screen to "sit" on. So, if you go to service center they will tell you it is because of pressure you put on it (your fault) and not because the margins are not hardened.
