Freezer not freezing

[Rfavero]

I have a 2011 sprinter which is winterized and parked in trailer park and still open for use. Heat is off and fridge is running on electrical. So far so good but the other day I noticed food in the freezer are no longer frozen. Ice cubes are still frozen due to outside weather (around -7 to 0 celisus). Stuff in fridge seems cold. Was working all summer with no problems.

I opened outside vent to check fuses, electrical plug, not dirty, etc. all good.

With heat off and cold outside my assumption is that the freezer should work?

I didn't check panel (will do next time i am there) and will try running fridge on propane to see if its an electrical issue. But I don't want run fridge on propane for 4 months.

Any thoughts?

Thanks in advance.

Roger