Auto-dimming is activated when the same picture is displayed for a long time and there is no mouse or key activity. This saves energy. I have not found a setting in the menu to deactivate this function. Since I use this monitor mainly for flight simulation (hardly any still images), auto-dimming is not a disturbing factor for me. The brightness is not reduced excessively. The slightest touch of the mouse restores the original brightness. This function has not bothered me during other activities (text editing, image processing).

It's not a problem when gaming. Otherwise, it's not really annoying unless you read a lot of text, which makes it darker.