It should be lighting. I have found that I sometimes have to use the lighter to heat up the sensor a bit, before the pilot will stay lit. I also noticed that the pilot will get bigger, the hotter the sensor gets.
When I got my camper new(2007), I also could not light the pilot. Rather then drag it back to the dealer, the dealer allowed me to swap parts. Thermal coupler(flame sensor) first, did not fix it. I ended up changing out the whole gas value for the oven to fix the problem. My dealer provided the parts at no cost.
Robert Wynkoop