That is correct. It run with generator but not 110 shore power.
That's a tough one there and goes above my pay grade. There are a few here that are really good with the electrical systems. The power divide between the two sources is so close to the input location it would seem almost impossible for this to happen. Check the power at the pole or have someone do this. It could be one leg of the power supply (50A) is not live or your power cord is damage inside somewhere.
2018 THOR Chateau 35SF
Two Labs, Bugsie & Blondie