I have owned my TV for approximately 3-4 years. the screen size just changed and it is now difficult to see my app screen (amazon). It is defaulted to standard size (which I assumed it always was on) and just now it is larger. I see that another post state that changing the size is greyed out (which it is on my tv as well). I am not sure why my size changed and would like assistance to restore the size to my previous setting. Thank you.