This is a two year old post with no info at the time, so I might not expect to get a response from the OP!
But when I look at this, I might propose an idea to check??
Do you have a frig manual in the big bag of tricks that should move with the RV? First stop for ideas and help?
If you look for a manual on that specific frig online, you may find a good troubleshooting section or at least a good parts drawing.
I have no real idea of what and how your model frig works but it is logical that ALL have some form of thermostat. That item works much like what we have at home to control the temp, either for heating colling of the house or of the frig.
It may be that thermostat or wiring is not working correctly to keep the temp stable in the frig.
As a first thought, I might wat to find that thermostat and make sure the connections for the wiring to it are good, clean and solid.
What I don't have any ideas on? Its the location and what type thermostat is used.
Much older were easier to take the probe off the cooling fins and test them in a glass of ice water.!
Maybe as simple as the connections come loose as the frig makes them cold enough to contract slightly?
First thought that may not mean much but just get the ideas flowing!