Have 3x systems with similar behaviour. All 3x 3phase systems with Lithium Batteries in ESS mode. When grid fails, loadshedding, get inverter overload error and inverter switch off. Need to manual start with toggle switch. We can switch the main breaker off 100 times and no problem. When the council switch off the grid then overload. It sometimes is preceded with low battery voltage message VEBus but voltage does not drop under 53V. Most of the time it happens at night when there is very little load. Have quadruple checked wiring and comms cables and fuses etc. Have set the V mains disconnect higher to 200V on one system but still issue remains. Can have a look at system called Carreg Crescent for example. Our very experienced distributor for 12 years now also not sure what can cause this. Help would appreciated.