Mine is often offline every week. At least once a week. Have talked to the Goodwe people but yet no solution. In retrorespect we should of got a cheaper version like Growatt. The wifi dongle or server is an issue. However, Goodwe support keeps on blaming our internet connections. I have one friend which I have referred got the same inverter and his is offline more than twice a week. The other issue is once it is offline, it is off for the whole day. It doesn't come back on or reconnect until the next morning when the inverter turns on again. Sometimes, it is off for several days. I definitely wouln't recommend Goodwe. Any cheaper inverter works better. We are just disgusted with their app, dongle, server and service. They do not have any technicians to come out to site to check. Have spoken and complained on more than 7 occasions, it has still ongoing and not yet resolved.