With my SMB build if the GFI power outlet inside the van trips, the other outlets won't work either. Does the test switch work? You can test it with a meter if you are qualified or feel comfortable working with AC voltages.
2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer
Yes, it will shut off all the other outlets too. When I bought my first SMB the seller gave me a big discount because the AC electric system wasnít working. When I got it home and started looking into it all I had to do was reset the GFI button and everything worked fine!