This is an ongoing problem, and I am sure it is me. We started with a cab over camper, went to a 5er, and now have a 29' Type B+. All were new when we bought them. In each case, I have had to defrost...
I got ice in all my RV fridges over the years. Just moister build up. I empty mine and use DW hair dryer to defrost. Does not take long. Only have to do this a few times a year.