If you are concerned just keep it on high setting although the first set of temps were not too out of line either. We use an internal fridge fan we purchased on Ebay for about $12 that runs continuously and is comprised of two very small computer fans. Where most of the cooling inefficiency occurs on RV type fridges is when the door is opened frequently, having constant airflow will help with dispersing the cold from the contents within aiding in quick temp recovery.
Main reason RV fridges perform inadequately is improper installation from RV manufacturer. Exterior fans mounted on the rear of your unit can help with required airflow needed for optimum performance. Our Dometic has performed well at ambient temps of 10 degrees to over 100 degrees, we do lots of our RVing without power hookups and prefer absorption type fridges as they have performed well for us over the couple of decades of RV ownership.