There's no explanation. I manage 8 Windows 10 Pro computers, and the jumplists have disappeared on 6 of them. I don't understand why they're still working on the other 2.
The only thing I can think of is that the updates came automatically on those 2, and on the remaining 6, I clicked the "Check for updates" button before they started checking.
I restored the backup and let it update automatically, and the error appeared again, so the error isn't from pressing the button.