It's not the solar inverters themselves that are usually internet connected, but rather the controller box (some kind of embedded system) that is internet conne

It's not the solar inverters themselves that are usually internet connected, but rather the controller box (some kind of embedded system) that is internet connected to allow monitoring and control. Perhaps this manufacturer decided to economize and make both of them part of the same "box", with the result that an error condition in the controller would result in the non-operation of the inverter part. Some systems like mine (Enphase) do a good job of letting the inverters operate independently of the monitoring/control software. But to do this, I believe they need to add data storage to the inverters themselves in order to log data during a controller "outage".