That said I do own the 50 inch model of the Toshiba Amazon Fire TV and it will show some cloudy spots if I use the usual test that reveals such. What test? Use some PC or such as source and then use some app to show 0 to 100% black to grey to white screen. This always shows where LCD panels have clouds. So far in all sub 1K USD sets, all will have a cloud here or all over.
The only time I didn't find those clouds was on Plasma and now, OLED sets. The take away is pretty simple. Either you pay thousands for the bleeding edge LED (I never suggest that) or run back to some old Plasma or a new OLED if you demand no clouds.