New XPS 8920, wake up problems?

Helping a friend set-up his new XPS 8920. Basic computer, only 'extra' purchased was a display.

I connected everything up, and checked the system. Updated all s/w that needed to be, installed some other s/w and a printer. I installed TeamViewer in case other help was needed and left.

Well he called and had a problem with a 'black' screen. Prior to this desktop he had a laptop. It was always on. He just closed the lid when done and re-opened it when he wanted to use it. Desktop came back after he opened the lid.

Well I know the PC went to sleep. So I told him to 'jiggle' the mouse. Nothing happened? OK, press the spacebar on the keyboard, nothing happened? Lastly press the power button, and that brought the desktop up after a short delay.

So I connected with TeamViewer and started poking around. First was the Mouse and Keyboard settings on the power tab. Both had checked to allow the device to wake up the computer? Since these were connected to the USB ports I checked in Device Manager all the the USB devices power settings to make sure they were NOT turned off to save power. Some were so I unchecked those. However my older XPS 8700 did have those checked, but I changed them anyway.

Still, the only way he can come back from sleep is to press the power button? The keyboard does have a SLEEP key that requires the FN key to be pressed at the same time, and when doing that that does put the computer to sleep, but the same key combination will NOT wake it up? Only the power button will do that?

He is using the DELL POWER plan. I am using on my XPS the BALANCED plan, but that should not matter?

I checked with a friend that has an XPS 8900, and on that machine only the SPACEBAR or SLEEP KEY will wake-up the computer, the mouse will not? They had not tried the power button but I assume it would too.

Am I missing something? Shouldn't the mouse and keyboard both wake up the PC? Is there some setting I missed?