Galaxy book keyboard backlight doesn't turn on

After first opening the lid/screen the keyboard lights up then goes dark, but it doesn't turn it on when the room is dark, I press Fn+F9 until desired brightness. I know there is a light sensor that turns the backlight on/off depending on the brightness of the room.. I've looked through online help and forums but haven't found anything current and no settings to change. Anything I can do so it turns on when it's suppose to?