Spotlight Cam Pro with solar will not charge

I have 3 cameras installed. Two are Spotlight Cam Plus, one is a Spotlight Cam Pro. All 3 cameras have Ring Solar Panel, 2nd Gen, 4W connected to them. Both of the Plus cameras charge well, but the Pro camera battery never charges and the battery drains to 0%. The solar panel for the Pro camera gets at least 6 hours of direct sunlight a day. In the Ring app, the plus cameras show the battery icon as green, with the sunlight symbol during the day, and the lightning symbol to indicate they are charging. The solar status is shown as connected and "A Ring solar accessory is connected and able to charge this device."Also in the Ring app, the pro camera shows the battery icon as green with the sunlight symbol during the day, but the lightning symbol never appears. Eventually, the battery symbol turns red as the battery level drops. The solar status is shown as Connected with no other statement. I have installed a 2nd battery in the Pro camera, which charged well in another camera. It appears that neither one of the batteries are charging from solar. I have tried rebooting the camera, unplugging and reconnecting the USB-C cable, and adjusting the solar panel position with no change. What else can I do to get the batteries to charge from the solar panel?