Thanks guys for the post-back.
Different monitors, GPUs, drivers, mouse, etc. I think it's system specific. That's why Known Issues said "may".
I tricked it by not doing what it said to do. I toggled back and forth between
150-100-150,
without logging off in between, as the message suggests. Settings held and Action Center is ok. BUTTTTTTT, on sign-off/restart/shutdown, it goes right back to broke.
It's not updating the user hive in the registry correctly, and not saving on exit.
It's a quick thing to do, so I'll wait for next build before I complain again in Feedback!
EDIT: Just noticed...both of yours are at MS "Suggested". My "Suggested" is 100%, which is unusable to me. Maybe a factor, who knows.