Swap the "Grand Constant Fault Interrupter" for a good 20-amp Hubbell regular receptacle. End of problem. Forever. I only use GCFI on my kitchen counter receptacles, bathroom, and outside weatherproof receptacles. Does your freezer have lots of exposed metal to touch? If no, it's a moot point. if yes, I ground my appliances directly to the bus chassis. A burned-to-the-ground miswired electrical circuit in a Mexican RV park is testimony that safety saves lives.
The Hubbell is ten times the receptacle that Samlex (or anyone else) uses in their inverters. But the inverter itself is a good one - not worth condemning over a chop suey receptacle. A hundred million watt inverter the size of Texas stadium with a chop suey ground fault interrupter will do they same thing. if you are simply infatuated with the process of GCFI yank the garbage and replace it with a Hubbell (or Marinco GCFI)
Wanna see PROBLEMS galore with GCFI? Move here where offshore trade winds bring billows of tropical humid salt air. Yeah. Where many GCFI receptacles get loaded with salt film and don't work or they do not trip - ever.
Go to Harbor Fright. Buy their fat green pen voltage detector. Garbage the batteries. Replace with AAA lithium so they last ten years. Walk through your rig, wave the magic twanger near every single appliance, in fact anything affixed to the rig that's made of metal. If it screams, fix the problem with the appliance. I have a 3/4" old-fashioned D handle single speed drill. Completely aluminum housing. When it gets used, out comes the gloves, 'cause I do not trust salt deposit leakage. Strong boiling hot white vinegar solution cleans off the salt. For motors, trichloroethylene.
LASTLY I chose SAMLEX because down here, everything has a line warranty. What's a line warranty? When it passes under the "Bienvenidos A Mexico" sign, the warranty changes to four letters - S.O.O.L.