Having a problem connecting shore power. I have a multiplus 3000 120 16 together with 100/30 and 100/50 smart mppt with a Cerbo gx. When I connect the ac in it throws the main beaker on the dock. Tried not connecting the earth...same. If I disconnect the ac out all works good and charges my batteries. Now the weird bit. With the shore power disconnected the inverter powers the whole boat without a problem. Any ideas?