Screen brightness automatically adjusts to screen content, what to do?

I've recently noticed that the screen brightness on my Acer laptop automatically changes depending on whether the screen has dark content or light content. So the screen turns darker automatically, even if the brightness is always at 100%. Therefore, detecting dark content becomes even harder in a well-lit room, which is pretty annoying. Can one exhibit this function somehow?

Look here, maybe you'll find something: https://community.acer.com/de/discussion/533612/automatische-helligkeits-anpassung-abstellen