Glad you found the problem.
As far as the meaning of the "open hot" (ie: no power available) indication that was nothing more than a result of the tripped GFI.
In addition, I would recommend getting a surge suppressor that plugs into the power pedestal. Protect the entire camper. Not just individual items at the receptacles. Your air conditioner, converter and microwave are the most expensive items that need protection.
Want REAL protection? I recommend this:
It will protect from all the power problems that a park can do to you. It ain't cheap.....but it's cheaper than the air conditioner!