Go into settings. Under display click on eye comfort shield. There you can set a set time to go on and off. Or have it off totally. Hopefully this helps. Or pull then the top to all icons. There you will find eye comfort shield. If you keep your finger on it, it should take you to the settings to do what I mentioned before.
Drag menu down from top. Touch the words not icon and hit off. You can even touch the words flashlight not the icon and adjust brightness of your flashlight ;)