Right click on the desktop and navigate to the Intel Graphics settings. Go to power, then turn off "Display Power Saving technology". Restart your notebook. Fixed. Unfortunately, sometimes it will turn itself on again, I notice "sometimes" going from running on the battery, to charging the battery, switching to high performance plan, then switching to power saver, then switching back again the auto brightness BS will be on again, just repeat, and of course make sure adaptive brightness is off in you power plan settings.