Okay, so the contact cleaner actually did work. But, I’m not holding my breath.
When I first came home with my spray can I sprayed it liberally on all the contacts I could find. I reassembled the vacuum and tried it out. The brush did not spin!?! I separated the unit in both spots, resprayed liberally. I also opened up the dirt container and sprayed the internal connections again too. This time when I tried it, the brush head worked.
The next time I used the vacuum the brush didn’t start. But it did a few seconds later on the next carpet it did! And it has worked fine every time since.