I'm not sure what this means.

Your GFCI outlet could just be bad. The residential ones will sometimes be bad and trip for no good reason. I had one in my bathroom that would trip shortly after plugging *anything* into it, but it would be fine if I plugged something into the ganged outlet that was being protected by that GFCI outlet. In your case, it sounds like your GFCI outlet can't handle loads at the maximum sustained rating. I'd try replacing the outlet with a better quality one to see if that solves the problem.

The Mobile Connector has its own ground-fault protection circuitry built-in. The methods used by GFCI outlets to detect such faults will sometimes trip each other. It could be that simple, which would be unfortunate.

 

agreed - I had a GFCI fail about 2 months into a new house.

 

I understand we have a GFCI in our cars, and having two of them together creates a problem. The electrician we talked to said he couldn’t guarantee we wouldn’t have this issue without using the Tesla wall unit. I was all set to do the installation of a new 50 amp circuit and receptacle myself, but didn’t want “dueling GFCIs”.

 

The GFCI could be bad, or it could be rated only for 15 amps (some of those had overheat protection built in as well). Either way that indicates it could be faulty or outdated.

When you take the GFCI out to replace it, check for signs of overheating/melting in the wires attached to the back. The GFCI isn't really intended to protect against that (the circuit breaker is) but some of them are sensitive enough that it can "feel" the resistance from overheating, and trip.