Why is the screen backlight in windows 10 not maximum in balance. mode, although the sliders are at maximum?

Question

Iron

In power options, I have a balanced mode and brightness at maximum when powered from an outlet and from a battery. But, for some reason, the brightness (backlighting) of the display is not actually the maximum, because when I switch to the Maximum performance mode, the backlight increases. What?
I even swing sometimes, as in the maxim mode. production it automatically becomes less sometimes. I repeat, everywhere in any mode the sliders are at the maximum.

Answer 1

Check this option in settings:

Answer 2

This is just an assumption, but it is possible that a light sensor is installed in the computer. Watched such effect on iMac.

Answer 3

Isn't this a laptop? I once had a similar problem, reinstalling the firewood on the integrated video card helped.