This may be caused by the inefficiency of the graphics driver on your laptop, so you need to update or re-install it manually or through a driver tool. And the icon of the power in the right corner disappears. But we may find out sometimes that we cannot dim screen of our laptop when holding Fn key and the brightness key isn’t work.
Generally, we'd like to adjust the brightness of the computer screen to help adapt different situation. How to dim screen of my laptop when holding Fn key with brightness key is not working
