I have a 2020 Long Range S for which I bought the generation 3 wall connector. Installed by an experienced electrician. When I plug the car in, it charges for about 12 minutes and stops, then the three short red blinks appear on the wall unit. We have checked the voltage, wiring size and torque, etc., per the wall unit owner's manual. I think the wall unit is faulty. The local dealer says email Tesla, I email them and they don't reply. Any suggestions?