Hi Barb,
the issue I am still having is the screen going off(/black) and it requires the power button to be pressed twice to bring up the initial/wallpaper screen. The need to press the power button twice suggests that when the screen goes off, the Surface is operating
as it was, only now the screen is off - the first press behaves as it normally would and turns off the screen (though in this scenario its already off) and then the second press behaves as normal and turns on the screen.
It can be recreated in several ways but its requires the brightness to be 0% (though possibly up as far as 3%) and it involves a change in the on screen content.
One seemingly reliable way to recreate it is, with 0% brightness, put the surface into 'tablet mode', then on the desktop select 'Pinned tiles' from the left hand side-bar. Now select 'All apps' from the left hand side-bar. Wait 15 secs (the screen brightness
should suddenly increase greatly during this time). Now select 'All apps' from the left hand side-bar - screen should almost immediately go off.