Follow-up to my original post...the problem has continued intermittently for the past year. Then I finally realized what the problem was: Sometimes I park my RV in the driveway head-in; sometimes head-out. When it's head-in, the fridge side of the rig faces west, right into the afternoon sun. Even if the ambient temp is not high, the sun hitting directly on the fridge side of the RV all afternoon causes the fridge to take 2-3 times as long to cool down vs. when the fridge side is shaded.
Like many problems, what did not seem to make any sense at all becomes incredibly obvious once you figure it out.
