I downloaded the ISO from:
https://www.microsoft.com/en-us/software-download/windows10
My Display > Graphics have nothing set -- no Hardware-accelerated GPU Scheduling, and no Graphics Performance Preferences set for any app.
At this point I'm considering going with the Windows 11 upgrade installer, and then reverting back to Windows 10, to see if it leaves in any better shape. What do you think of that?
That's what I suggested you: to add the store and let it run on the Dedicated Graphics Card.