EG4 Defect

I had a real problem with two EG4 18k PVs. When the systems ran separately, they worked fine. But when paralleled, crazy things started happening and eventually burned up a lot of appliances in the house and one inverter. Took them months to figure it out. After all the time I spent switching inverters on their behalf and repairing all the appliances that were ruined they will only replace the units that quit working but not the damage that they caused inside my house.