I temporarily cut the power to the electricity grid and to my photovoltaic system to insert a new socket in the house.
When I restarted everything, the system gave no signs of life and it's still all off.
In particular, the 2 US 5000 Pylontech batteries light up regularly, the colored lights are correct, they do not give alarms but they do not produce voltage.
Could it have happened due to the wrong sequence in which I restarted the system?