Electrical Issue

Circuit Breakers, GFI's spark when connected to power and when they disconnect. That spark builds up carbon on the metal elements and the carbon causes voltage to drop and is perhaps causing your GFI's to think there is a short. The first thing that indicates bad circuit breakers and or GFI's is a smell of the encasement around them to oxidized and finally melt. That is present in may RV's due to the overloading and low voltage coming from the shore supply,( plug in to power ). Start at the supply in point, and clean the contacts on the RV male plug terminals. Then check the electric connections at the RV circuit breaker box, including the tightness of the wire hold downs, and the breakers themselves and where the connect to the main breaker entrance bars. Sometimes if you shake the breakers, (when they are out), you can hear the inside components move around and hit each other, which means the spring motion is too loose due to age and use. Of course do all that when power is off, shore and generator.