Hi,
Just to add to this. I have 3 machines, EIS installed on 2 (both relatively clean Windows 10 installs), the other machine is just MS Defender.
This issue is definitely recent. The last couple of days I've been thinking there is problem on the 2 machines, feels like there is no hardware acceleration when dragging Windows around the desktop (though gaming performance is fine). Similar to not actually having the GPU drivers installed (I even checked all was good in device manager).
I read this post at lunchtime at work, just got back in and checked Task Manager on all machines. The 2 units with EIS not showing GPU as others have said. I've run the commands on both, GPU is now back on both machines, I've rebooted and no longer have sluggish performance when dragging Windows.
The 3rd machine is MS Defender had not stopped showing GPU in Task Manager.