On My MacBook Pro 13’ I do have a faint blue line on my screen. You Could try Pressing Underneath The Screen, On the Black Part. It did work for me But every time you restart or run out of charge it comes back. If you try this method get ready to Press Underneath The Screen A lot. This Morning I saw there was the line on my screen and i tried doing my method And this Time it didn’t Work. This is a temporary fix.