I had a SunSaver 20 amp controller go bad, and they sent me a new one. The failure was preceded by my having the rig in indoor storage, plugged into shore power.
I left the solar panels connected. The result of that was that the battery voltage was higher than the panel voltage. The MS tech said that can create an error condition in the controller, but that it should be able to be cleared. But the controller had gone bad.
I don't know if the condition of indoor storage with everything connected caused the controller failure or not. I mention it in case it applies to OP or others in the thread.