I just purchased this new laptop a couple of days ago and love it other than one thing. The screen is too dim when unplugged. It is great when plugged in, but dims quite a bit when it is not. I have the brightness at 100% for both the on battery and plugged in settings so I have no idea how they vary so much. I have it set for high performance, not power saver. The battery saver is also off. I have looked all over the internet and found no useful info.
Please try the following;
Right click in a free area of the display and select AMD Radeon Settings
In the left of the windows which opens select Preferances
Then Radeon Additional Settings
Expand the Power option and click on Power Play
Turn off / disable Vari-Brightdisable Vari-BrightOnce you have applied this change it should then be possible for you to choose your own screen brightness on AC and battery by modifying your chosen power profile in Windows advanced power settings.