One issue for the older (1970s and 1980s) RV heater and stoves are the thermocouples that register there is a pilot light before opening the main burner valve.
I had both the oven and furnace ones get internally corroded, I think due to condensation over the seasons of non-use.
I took a propane torch to the thermocouple and heated each one until it was red hot then let it cool off before trying to light the appliance.
The one in the oven gave off a green flame before the torch got it completely heated up and I think that was some of the corrosion burning off and allowing it to work properly.
Both work properly three years after the fix.
Easy enough to try.