Inverter Offline

My inverter went offline on the 6th December, I believe it is all working but I cannot connect to it through my mobile app or the website dashboard. Have tried full system reset. Anyone else having this issue?

Have you tried turning EVERYTHING off. DC string breakers., turn battery off (button high on RHS on 9.5, hold until it beeps). Inverter MCB in consumer unit. Any DC breakers between battery and inverter. Battery DC breaker. etc. Let all lights go out and leave for 30s or so and then turn back on. Should reboot battery board and inverter board.

Can you login to your router and see your inverter? Should be HF-21 or something. Try assigning it a fixed IP address, so the router finds it more easily. Turn off 5gHz on router until you get a connection.
Make sure router security is WPA2. Anything else and dongle cant' deal with it.