Also want to show my ignorance; Will the EMS trip if the open ground is on the load side, or only on input side?
I read often that CG electrics may not be great. I can easily see how they could be under sized for all the power demanded. (Bell, some states have that issue) But if you think of the liability a campground would face from a open ground I can't imagine that problem would not be addressed.
Now if EMS only shuts off for incoming problems, the OP should report to management. (Might be best anyway, so they know should check their snot) But if it is possible the EMS saw a problem with the RV should the OP get somebody to check his stuff out?