Not saying this is your problem but many RVers have few screws loose.
When My Damon was "Sticker in the window" new sometims one A/C worked, sometimes the other, both or neither. I decided to tribble shoot before I took it in. Opened the AC-Distribution panel (Also known as breaker box) and one of the screws took 3 1/2 turns to tight.. Several others were loose as well.
NOTE Unplug from shore power. NO running of generator while working by 12 volt light (house light)or flashlight in that box..
But that's step one....
Two things about this advice
1: Your free is cheerfully refunded (the ultimate money back guarantee)
2: those screws. if loose, are a fire hazard. If tight, they are not.