Phoenix Inverter 12/1200 230V, firmware v1.36, restart problem

Phoenix Inverter 12/1200 230V, firmware v1.36

If I change something in the settings via the Victron Connect app, the inverter has to restart. Unfortunately, the inverter then does not start. And I lose the remote connection to the Cerbo Gx because it is supplied with power by the inverter.

So I have to switch the inverter on and off manually on site. I have the inverter running in Eco mode.

That is why it is not advisable to power the cerbo from AC, it is supposed to be connected to the battery.

I have checked the Cerbo Gx is connected to the battery, but the GSM router is connected to the inverter. This causes me to lose the remote connection.

Why does the inverter not start if it is supposed to do so? Something is wrong with the inverter. This should be solved via firmware or something similar. Who do I need to contact?