Solar charger status

I have a ring 2 doorbell with solar charger. In the app the “solar charger status” is “add a ring solar device”. Clearly something is wrong here, the doorbell doesn’t even know it is connected to a solar charger. What is the most likely issue or should I just return it? South facing etc is irrelevant here and the connection is very simple, surely not a physical issue? Advice welcome, looks like a dud.