Surface pro 3 Brightness control missing

I have the exact same problem

I reset my Surface Pro 3 using a recovery USB a few days ago, and noticed the issue today. Manually installing the Intel HD Graphics from a zip file didn't resolve the issue. When I did Device Manager >> Display adapters >> Update drivers >> Let me pick … >> Browse … >> Microsoft Basic Display Adapter, it seemed to do the trick, but the display became terribly laggy, and the problem came back after a restart.

Update on this:

Plugging and unplugging an external screen will reenable the settings for brightness so that you can at least interact with them, however as soon as you try to actually move the slider it doesn't in fact change the brightness and the settings window crashes.

I'm having the same issue (brightness slider in right hand side disabled, the setting "automatically adjust brightness" just vanishes from the settings>display options, as well as my power button no longer putting the surface to sleep.

However I've realised that when I plug another monitor in so that my display is extended, the settings come back and I'm able to adjust the brightness of the surface pro screen. As soon as I unplug the additional display, all the surface brightness options are disabled / removed. 

The power button still however doesn't put the surface to sleep.

Is anyone else experiencing this behaviour?

Same problem here!

Also my power button does not turn off the screen!

And also the screen does not go off when the surface is folded on the keyboard like it used to.

This is absurd one would expect outstanding stability from a Microsoft own device after so many years from its release