Intermittent Warming on GE side by side. I need help trying to solve this problem. I have a GE

Question

I need help trying to solve this problem. I have a GE side by side refrigerator/freezer. Every two weeks, the refrigerator side becomes warm (60 degrees) . I defrost the machine, and both sides work for two weeks. I have done this three different times and it's the same thing......works to two weeks, gets warm, I defrost it, works again---for two weeks.