System was working, now AvsF shows green screen. (updated)

(Sent in a bug report, but figured I could ask here too)

Windows 10 system was working fine.  I re-ran the "Assess System Performance" feature for kicks and now I never see image output from SVP (audio plays).  Also the GPU list in SVP Control Panel->Application Settings->GPU Acceleration looks wrong.  All my real hardware appears twice (2 x 1080ti + 4600 Iris hardware = 4 x 1080 ti + 2 x 4600 Iris entries), and I see the Microsoft Basic Render Driver as the bolded default (that's for if you have no GPU + driver).

I've tended to use MPC-HC x64 with ffdshow filter, but I've tried AviSynth Filter too.  Tried uninstalling all parts except the control panel, then reinstalling.  Have reset all SVP settings a couple times.  Re-ran the Assess System Performance a few times.

One oddity was only one 1080ti was ever tested in the assessment.  In the past it tested each card as if it might give a unique result.  Now I see the CPU test, 1080ti test, a big jump in progress, then the 4600 Iris test.  SLI is disabled.

Turning off both SVP's filter options lets me play videos like usual through LAV.

I'd had AviSynth+ 3.5.1 installed before.  I tried upgrading to 3.7.2 after the issue happened.  No improvement.  Tried reverting...oddly the version string says 3.5.0 now in the event viewer.

Tried to post part of a log here, but I think it's blocking my post.  No playback time errors in the SVP Control Panel log that I can see.

Attaching AVSF log from enabling the registry key.

One weird thing I'd done was to switch IRQ modes on my video cards from the legacy line based way to "MSI" queue based.  Hadn't seen anything bad, but thought maybe that made the assessment unhappy.  Disabled the feature (+ rebooted), and reran the assessment...no change (still have the double GPU entries and the basic/fake adapter too).

I can't find a debug log with errors to point to.  And other than the images not changing, I've periodically found a process using a bunch of CPU time that I have to kill.  Guessing its the frameserver that got stuck in an infinite loop of some kind.  It's usually called "mpc" in task manager, and is a background process separate from the windowed player.

Only thing left I can think of is the G-sync setting is now on.  I found out my monitor has Variable Rate Refresh (FreeSync) so I turned that on.  I guess I'll try disabling it and see if anything changes, but I doubt it (no idea why that'd impact SVP in this way...and only after rerunning the assessment).