W10 Hanging, UI functionality but nothing else

I have a strange issue on a fairly wholly new setup. A month old.

About once a week W10 will Hang.

This is the third time it happened, took my dog for a walk, came back, unlocked the Desktop user and I'll have problems. It never happens when I am active on the Desktop, only when I leave it for a while, like work, sleep or .. dogwalks, in this case.

Here's what happens:

Explorer.exe's UI will be responsive, in that I can open tabs like the start-button, the settings icons are there and they branch out into restart/shutdown/etc, but I can't open anything and clicking the restart or shutdowns does nothing. I can close some folders and programs that were already open, and others will simply not close, even if the mouse-clicking has visual feedback. I cannot start any programs and no keyboard hotkeys work, like Taskmanager or Windows + R. I am eventually forced to reset.

It's as if Windows was sitting at the table and then just got up and left.

I checked the Event Viewer on windows system-logs and they just stopped for an hour while I was out with my dog, from 14:06 to 15:43 (which is when I hit the reset). It had some errors that seemed benign to me prior but the last two were Service Control Manager Information before it stopped "Thinking". Table and details bellow.

Spoiler: Event Viewer System snippet

I TRIED:

I thought it might be the CPU shenigans trying to save power due to C-State. Tried disabling that last week. That didn't work otherwise this wouldn't have happened. Re-enabled it now. Also ran a windows memtest and found no issues.
Tried changing to maximum powersettings in windows controlpanel but this is a Desktop PC, not much hope there.
I did DISM and sfc /scannow in cmd after today, maybe this helped, time will tell.

Spoiler: System Specs

When I am googling this stuff the common problem I see is that either the entire thing is frozen or you have mouse-control but can't click or interact with anything.
I CAN move and click things, even close some windows (even if clicking on anything in the window doesn't do anything). I can open the start button menu and even see the shutdown/restart commands, but clicking them does nothing.

I can mess with the UI, but have no functionality.