I think this is technical, it's more hardware...
I have no ill effect on performance, everything still works fine.
I've just noticed that the screen is no longer perfectly flat. While it is flush with the plastic case in the top left corner, it's sunk down in the bottom right by a small fraction. Less than the thickness of my fingernail. Small, but noticeable.
Anyone else have this? Is it normal? Could it cause a problem? Or is it some normal thing that I shouldn't worry about?