Doesn't have it enabled? What the hell are you talking about?
You have an AMOLED screen. If something is on your screen, but the screenshot won't show it ... points to a hardware problem. All ROMs still show it? Hardware! Only shows on light wallpaper? BURN IN
Burn In is an effect where the LEDs burn out faster than other LEDs. If you have a static image on the screen for a long time, such as nav bar, those pixels will wear out faster than the others, so they won't be as bright. It will be hard to see unless your screen is mostly white (light wallpaper) in which case the damaged pixels be dimmer than the pixels next to them. Does that sound like what you see?
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