I had this problem when I first got the '75 Argosy. I found that the gas pressure was lower when only the refrigerator was on than the spec for when half the appliances are running. I got a new regulator and now my refrigerator stays lit.
If you measure the gas pressure and find that it's OK, and the burner and flue of the refrigerator are clean, you can then try managing the airflow through the fridge locker with an air filter or something, but the bottom-inlet/top-outlet setup is pretty good most of the time.
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill