So, wow, this is even weirder than I thought it would be, but it isn't LOS 20 or the Pro1 itself, so that's a relief.
What was going on, and it seemed to be new behavior coincident with installing LOS 20, was that when I connected my Pro1 to the USB 2.0 hub to charge, the lightning bolt would appear and then it would go off. So then I tries a 2.0 cable to the wall and it was okay. Then I tried to a USB 2.0 port on my Linux laptop and the same thing that happened with the hub, Lightning bolt came on, then went right off. That's when I remembered that the USB 2.0 hub is connected to my