A GFCI is a safety device and tripping means there is the potential for dangerous voltage on all grounded RV metal. What is now preventing this is an earlier required safety device namely the ground wire.
We all want to think our RV has a good ground. Maybe it does. But what about the pedestal and everything upstream? And especially the pedestal plug. I've seen many worn or damaged pedestal plugs.
This is one reason why I've posted plugging into a 20A GFCI and checking your RV. It's very rare for a 30A or 50A pedestal plug to have a GFCI to protect for a ground fault.