There is a tendency in the summer to keep selecting lower settings when the fridge is having a hard time keeping up with high temperatures. Then, when it gets cool and the fridge can overcome the ambient temperature, things freeze. It happened to me years ago on my first trailer.
I'm super careful since I keep insulin in the fridge and it can not be allowed to freeze.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10