A belated welcome to iRV2 , first post I see.
Some RV's had a propane leak detector with a control that would shut down the propane solenoid , to cut flow in the event of a leak/alarm.
If you can pull the leak detector and check the wiring and the instructions on the back , look for a wiring diagram that includes a wire to the solenoid.
Most detectors set up to control the solenoid will have at least 3 wires some 4 or 5.
You may have a blown fuse for the detector, or a defective unit.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.