Dometic fridge woes.

I have a Dometic RML8555 3 way refrigerator and have the same problem except that mine came like that brand new from the rv dealer. Worse, I have two friends who have the very same rv that were purchased new about a year before and a year after me who have the same problem and contacts with Dometic makes things worse. They tell them to take it in for diagnosis at an authorized Dometic dealer who does work on them and charges the customer for the work because Dometic says it's not covered under the warranty! I run my fridge on 110ac as it comes from the inverter because it gets colder than the lp mode.