Check your lines! As these classics age these propane lines can deteriorate. After sitting I storage for a few years I opened the liquid valve to check the generator. Found a small leak!
The line was routed across the top of the tank and connects to a hard line that crosses the coach to the generator where there’s another short hose. That one had been replaced. Bet they would have done them both except you have to drop the propane tank or black water to get at the coupler.