Since you have no ATS, then the only options can be is that A) the genset is not putting out power, or B)there is a breaker/fuse or some other interruption between the genset output and the coach. Since everything works from shore line plugged into campground, then you can eliminate a bad cord/plug. If you don't have one, get a good volt/ohmmeter for diagnostics. They are not real expensive and will tell you LOTS of information.
Re-check the breakers that are on the genset to make sure they are turned on (I know because it happened to me and I troubleshot the heck out of my system trying to figure out why I didn't have power from my genset. Turned on those breakers that had apparently tripped and everything was fixed again.) Check the outlet from the genset where you plug the shore line into. If you still don't have power there when the genset is running, then perhaps a wire has come loose or is not making good connection to the outlet, or the outlet itself has a bad connector and is not allowing the plug to make contact when plugged in. Shut down the genset and check the wiring to the outlet and contacts inside the outlet. If all that is good, then check the brushes on the genset itself to make sure they are making contact with the slip-ring. Sometimes a simple spray of contact cleaner on the slip-ring/brushes while the genset is running is all you need. If you still don't have power after all that, you may have a bad voltage regulator/circuit board on the genset.
Just some thoughts on how I would go about trying to diagnose the problem.
