Right after the fuel passes through the orifice (which makes sure a specific amount of gas is released), there are two holes which mix air into the fuel. I wonder if there is something in that part of the assembly which is blocking one or both of those air holes. Bugs often get in there and block up the orifice.
If you want to look at this yourself, you'll need a phillips head screwdriver and two wrenches (adjustable or open-ended). Make sure the fridge is off. Open the lower grill on the side of the camper - turn each lock 90 degrees then the whole thing will pull out. Then look for one screw to remove the metal wind screen around the burner on the lower-right. One more screw will allow the burner assembly to drop down, but it will still be attached to the gas line. You can pull it towards you gently just don't pull it so far that you kink the line. One more screw will remove the lighter and temperature probe. Use the two wrenches to remove the rectangular burner box (I think that is the right term) - put one on the box and one on the nut at the end. Be careful here because you don't want to lose or damage the orifice inside. Once the box is off look for any clogs.