Dometic Fridge

I'm going to take a shot and guess your fridge is in a slide. Fridges worked much better prior to slides when they had a vent directly overhead and air circulation was much better. We have a Norcold but the same issues apply to them when they are put into a slide and have to rely on two sidewall vents to carry the heat away. This is what I did this year. Waiting for the coming summer to see how it works on really hot days but so far, so good. May still reverse the airflow as I originally intended if I find it necessary.
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29770712/srt/pa/pging/1/page/1.cfm