What year Sunseeker? Only in the past couple years have Forest River moved away from a special receptacle that your generator uses for power to an automatic transfer switch. I'd almost be certain the shore power needs to be plugged into the gen outlet.
If that isn't the case, check the breaker on the Onan generator itself. That might be tripped.
It is a 2013, I will have to recheck the circuit breaker again. It seems pretty flimsy but seemed ok. I don't see a special receptacle. If it ever gets nice out I will check again. Hope the rain and snow stops soon.
Thanks Dave