Hello again!
We have the same model fridge freezer in our RV and find on 110v it just isn't as effective as running on LP gas, especially during windy weather. I guess a 300w heating element just isn't enough when it's either very cold or windy.
I hope that yours is now properly sorted, nothing worse that ruining all your frozen food!
You're right that it runs colder on propane but I find that it usually is cold enough on electric. We haven't had any problems since I worked on it last week.