I have a 2.5 year old Whirlpool apartment fridge/freezer (I believe WRT112CZJZ).

It is kept in my garage but my garage is heated, so it's typically 50 degrees in winter. Maybe briefly to 45 but never below internal temps.

A few weeks ago everything in the freezer thawed out, fridge felt warmer but hard to tell, since it's seldom used and in a cool garage.

I unplugged and re-plugged, nothing happened. I turned temp up/down and then it kicked on. A week later it quit cooling again. I unplugged and re-plugged and it fired up and ran for two weeks. Now we've noticed the freezer is warming again. Unplug/replug did nothing but then hitting the quick cool made it fire up.

Something is not activating the cooling cycle but it's apparent it is capable of cooling, when running.

Does this sound like a thermistor?