We bought an almost new 2021 Ethos in January. The Norcold DE 105, 3.7 cu ft. Frig. goes from working just fine to warm in a matter of hours. It continues to run but doesn’t cool. If I turn it off and start it up the next day, it’s good for a couple hours only. I’ve heard of this problem. Anyone know what’s wrong and how to fix it? It’s a major disappointment right off the bat. Thank you. Wm. Burns