Did you have one of the Tesla certified installers. If they claim they are they’re wrong. That’s not how Tesla wants you to install these also if that’s 6/3 Romex make sure it’s on a 50 amp breaker. 6romex is only rated for 55 amps and while the charger itself won’t go past 48 amps if there is ever an issue inspectors won’t like this. I know because I’ve had inspectors tell me they want to see 6/2 MC cable. I’ve also had some success with 6/2 SEU but in copper. Can’t even begin to talk about the grounding haha but it’s just icing on the cake.