Far from an expert on this, I can tell you that the fridge is designed to run while driving down the hwy. I am taking for granted that when the slide is out the fridge works on propane. When the slide is out and you are not of shore power does the fridge work? Reason I asked is that you need battery power to make the fridge work. If your coach batteries are weak this may be the cause of the problem.
Hope this helps a little