I’ve had my solar panel for about 18 months now and it has stopped charging my stickup cam and I know why. The plastic connector cover had turned brittle and cracked which allowed moisture to get in and literally rusted the connector from the solar panel to the cam. Thankfully the cam still works. Defective product from Ring though.
You should call up support and try to get a replacement. These things have warranties.
Did you have an issue installing solar charger by removing the mounting panel from the doorbell camera.