Why does the soft starter through the gas generator not work, but does it work from the network?

Good afternoon! Please tell me, I purchased the Extra Aquacontrol soft starter 2.2C soft starter for the UNIPUMP ECO VINT3 well pump. When connected to the home network, everything works fine, but when I connect the foreman 2800 to the gas generator, the 2.2C soft starter does not work. Only the LED is on, that the network is connected, and at the exit from the soft starter even the light does not light. One has only to connect to the network, the soft starter 2.2C works again, what can be? Tell me who can do what, I use only a gas generator as there is no light in the garden at all and it is not predicted that there will ever be one! Thanks in advance!