57031 screen only works intermittently - could there be a screen protector?

Could a worn out screen protector be causing my head unit's screen to only work intermittently?

My 2013 Prius 2 has the 57031 head unit - touch screen, no nav, no HD radio, no satellite, no backup. When the weather is cold or the car has been sitting in the shade, the touch screen works very well. But when the weather is warm or the car has been sitting in direct sunlight, the touch screen works very poorly. By "poorly" I mean only one out of 7 or 8 presses actually register, which make switching bluetooth connections between phones a bit of a chore.

I was looking at the screen and saw that there is noticeable wear on the screen in the rough location of the "connect" and "play" buttons (and one other that I can't remember what it does). I also noticed that I could scrape off the top layer of the screen with my fingernail. I have attached an image that shows the wear.

I bought this car used and believe it was well cared for. Does this wear look normal? Or is there some kind of screen protector installed? And if there is a screen protector, is there a way to safely remove it? Everything on the radio works fine, when I can control it.