Solar panel stopped charging Spotlight batteries

Hi there community - I have a Ring Spotlight camera with two batteries, connected to a Ring solar charger. In the 3+ years I've had my camera, I've had to manually charge the batteries once – until the last month. Now, it seems as though the solar panel just isn't charging the batteries. The solar panel seems clean, there are no obvious flaws in the wiring and the connection from the solar panel wire to the camera seems secure. The batteries are charging just fine when I remove them and plug them in. Any reasons why the solar panel would suddenly stop working / or the charging would suddenly stop charging?