I am having a very weird charging issue with a newly installed NEMA 14-50 socket. When I plug in the UMC to my 14-50 socket the Gen 2 UMC goes through the boot process, then the "T" in Tesla starts blinking red 5 times, and this will continue whether the car is plugged in or not. When I plug the UMC into the car, the car dash shows that it is pulling 240V, the charge port blinks the regular green, but the amps are restricted to 8A and I get a error message on screen saying check adapter. Going to the UMC manual trouble shooting section (https://www.tesla.com/sites/default/files/downloads/gen_2_mobile_connect...), 5 red blinking lights indicates an adapter fault. That being the case I have my electrician leave as I tell him I probably have a faulty adapter. I then drive down to the Tesla SC and they plug my UMC in with my adapter and everything works perfectly. Drive home and call the electrician who comes back out and checks the line (everything is pulling fine on a 50A breaker, showing 240V as does the car), he even replaces the NEMA 14-50 socket and upon plugging it in, same 5 red blinking lights. At this point I have no idea what the problem is and its driving me crazy. If I plug the UMC into the 120V socket using the 120V adapter, then everything works fine, no red blinking lights, charges perfectly fine. As soon as that 14-50 gets plugged in, the red lights happen. Looking for any suggestion that would help me out since I have basically ruled out the common causes for the adapter failure (SC trip), and socket failure (electrician re-visit and line test).
I also tried jamming the adapter into the UMC as much as it would go, since I know that others have fixed 5 red blinking lights due to the adapter being loose. I even kept pressure on the adapter while it was plugged in and no dice. I have scheduled another service center visit and I will have them provide me a loaner adapter or maybe even a loaner Gen 1 UMC to see if that works.