My monitor only has a gamma slide on one tab,a volume slider on the other tab,a brightness/contrast on the 3rd tab,and a Sharpness/Black level on the last tab. No power stuff anywhere in the menu opened by the monitor buttons.Look for "energy saving" feature in LG menu. It acts as adaptive brightness.
Glad to see i m not the only one who had it happen at random. Any luck with a solution so far,or am i SOL?yep, it's the monitor, been set in some auto adjust mode. my monitor has that too, it's annoying.