It sounds like an electrical gremlin with one of the transmission or engine control modules. I used to have a few similar episodes with my coach until I took the time to disconnect EVERY electrical connection that I could find with the chassis, engine, transmission, and house circuits. I cleaned and coated each connector with dielectric grease as well as coating the spark plug boots. This grease is available at any auto parts stores and I have not had an intermittent electrical problem show up since then.
As our coaches age, and because of moisture and other environmental factors, our electrical connectors can start to fail. Electrical problems, especially intermittent problems, can be very difficult to find and expensive to have a shop mechanic troubleshoot. I feel the dielectric grease makes sense as a preventative measure.