So at the campground no problems. Not a GFCI at pedestal. So it happens at home with a GFCI plug-in at stick house. Assuming the GFCIs that trip in the OP are stick-house?
Usually it is an adapter in the shore power cable string of cables from the RV.
Or the converter could be sharing its 120v CB with some 120 receptacles where one might have something plugged in that is tripping the house GFCI. Not the converter. You don't know if it is the converter (under warranty)
The outside 120v plug in can get wet while washing the RV too.
IMO live with it by using only non-GFCI plug-ins until it is convenient to get them to do the warranty work. Not to lose any camping time waiting for them