Thanks for all of the replies. Sorry I didn't get back sooner. I've been busy with other stuff.
I changed the inside GFCI that keeps tripping. It still trips. The RV has been stored in my garage for the last month since our last trip. I also changed the outlet for the fridge. I am having trouble keeping the fridge running on shore power. It does run on AC but only when I have the propane turned on. I am now supplying the fridge with an extension cord, with the propane off, and the fridge works fine. It's looking more and more like a ground issue with either the fridge or water heater. Thanks again.