Can1500w inverter or Honda 2k gen work 900w Microwave

MY brother travels alone and only uses the microwave to cook or defrost for s hort time. He only drains the 200amp bank about 50amps max and he has 400watts of solar which usually recharges the batteries.
Again, I will see him tomorrow at the campground and give it a full checkout. I think his microwave has his inverte overloaded and cutting out because of it. He called GoPower today but hasn't returned my call yet.