Even the residential absorption fridge we had when I was a kid the flame was not much bigger than the pilot light on a water heater. If you have a "roar" from the fridge, get out, and shut off gas.
You said the temp went up while driving? Any chance more hot air blasting by the box raising the temp? Might see if it holds temp while parked.
BTW, every time you open the door all the cold air falls out on your feet. The closer to full the better. When I was hosting in 100+ temps I would keep the fridge full of containers. When I remove a container of food, replaced with MT. (had a thermometer with sensor inside, outside readout. reduced the height and length of spikes)
