Wiring connections have a way of vibrating/shaking loose while our RV is bouncing merrily down the road. With your RV disconnected from shore power, remove the front of the convertor/AC breaker panel and tighten all wire connections, making sure the wire is fully into the connector. I had an intermittent short once, the circuit worked on one trip and didn't on the next. I read of the need to re-tighten connections in the power panel, so I did; eliminated the tripping breaker issue for me. FWIW, about half the connection screws were barely putting pressure on the wire.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"