Mostly Common Installation Failure
Please kindly see the zoom in image, the screen protector edge is not aligned to the screen side, its a little bit far from the screen left side, in this case, the right edge of the screen protector would definitely not adhere to the screen.
Since the screen protector is custom-made for the 8 inch Subaru navigation display screen. The length and width of the screen protector is almost exactly same as the screen.
So a little left or little right would make the screen protector not adhere to the screen.