[Motor31]

Have you tried isolating the inverter and just running a power cord from the gen to the washer to see if it runs normally?

I would also simply unplug the washer when not in use. It may be subject to the power surge when you start up the gen set. You might also have a surge protector between the electronics in the rig and the power socket. I have one for the TV, another for the stereo system and one for my computer. They are inexpensive insurance from spikes and the switch on the surge protector also means I can simply isolate each electronic device from the circuit to cut electrical use by those power vampires.