Not sure if I need a new converter or.............

I would check the 120 volt shore power connections.
If you are using an adapter, check for heat build up and discoloration on the pins.
I would take a little time and check connections in the 120 volt power distribution panel. Pay special attention to the neutral (white wires) in the rear of the panel. Look for any metlted insulation. I would suggest getting some electrical grease and re-terminate the conductors with a liberal amount og electrical grease.