Couple of questions:
- Is your refrigerator two-way (120v or propane) or three-way (120v, propane, or 12v?)
If it's three-way I'd suggest NEVER using the 12v option.
Regardless of that choice, do you leave your refrigerator "plugged in and running" while it is in storage? If you do, I'd suggest disabling it instead. There is likely a dedicated circuit breaker in the panel which will kill power to it. If you disable it (good practice,) be sure to unload it, leave the door ajar, and prop something so the door cannot accidentally close itself.
The refrigerator is one of the highest electrical loads in an RV, ditto the battery charger. If you disable the refer prior to plugging into shore power you will be demanding less amperage which might help your current issue.