100% off grid Victron EV charger tripping main RCD for house

I live in Spain 100% off grid with 9kW of solar, home built battery and Victron kit. I have a problem I don't understand, whenever I allow my Victron EVCS (the original one with a screen) to charge at 6kW or more the main RCD cuts all the power. I am originally from UK hence referring to an RCD.

Any thoughts from all the genius people who really understand EV chargers? 😉🙂