The only conclusion I can draw is that my USB charger has an electrical issue. If you are willing to send me a new one I will try it for a while in my Jeep before installing it on the motorcycle.
I will return the old one if you want it for research purposes.
I was going to buy a Powerlet adapter but after seeing the $49 price tag, I'm willing to try another $20 USB Charger.
I also sent you a PM.