Notebook Video, Display and Touch

[I posted this question on a different board but didn't get any replies, possibly because it was on the wrong board.  I'm reposting it here, as this might be a more appropriate place for this question.]

Okay, I am fully aware that this is a problem that has vexed many other users.  I have spent many hours over the last two months trying to follow the advice of people here, but like many others, nothing is working.

I bought my HP Envy x360 about 8 months ago.  From the very outset, I have had problems with the computer going to sleep after a period of inactivity, and then I can't do anything to wake it up.  Shaking the attached wireless mouse, pressing or using the touchpad or the touchscreen, and hitting every key on the keyboard doesn't work.  Ctrl-alt-delete does nothing.  The only thing I can do it hold down the power button and force it to shut down.

I have verified that the keyboard driver software is updated.  

I have gone to the "choose what the power buttons do" in the control panel and experimented with different settings.

I have changed the power mode/power settings.

I have gone to the Device Manager and checked the keyboard settings.  Indeed, for one of the keyboards listed (there are 3, which I don't understand since I've only ever used the built-in keyboard), I have confirmed that the "allow device to wake up" button is clicked.

I have stayed up to date with all Windows 10 updates.

I have downloaded and installed all recommended HP updates.  I have not installed all the optional updates.

I have updated the BIOS (but that was to try to solve a non-stop fan issue - which I will ask about in another thread).

Despite all these efforts, this still has not solved the not-waking-up problem.  This is rather frustrating.  I will acknowledge that I am not computer savvy at all, but I have done what I can to find solutions on this forum and elsewhere.

Any help?