Came to this site via Google. I have a Goodwe inverter that's recently stopped allowing me to change working modes. Since install last year was able to do this. I'm not an installer.
It was super useful for putting into Backup mode during cyclones and I was experimenting with Eco Mode which would allow me to charge from the grid at certain times (e.g. if I switched to a power plan with a free hour of power). I am now stuck in purgatory with my inverter charging my battery every night for the test interval I set up - costing me money.
I now simply get "Operation failed. Please try again", also the working mode and DOD display fields show --.