Im guessing there is no EMS on this unit, so if everything checks out at the pedestal, the next thing to check would be your transfer switch if it has one. If it doesnt have a transfer switch the next place to check would the main breaker in the trailer electical panel. So at this point it would be time to break out the multi-meter and trace the problem to the source and if this isn't a skill you posess its time for a qualified electrician. But maybe you’ll get lucky and find that hidden gfi….
Also year, make and model are always helpful. I know this is a 26’ Forest River, so at this point the year and model would be helpful and also any electrical mods, improvements, or additions. Also did you buy it new or ismit possible a past owner made some mods?