I have a 2 month old OpenEVSE charger with a 25 foot J1772 charging cable and a NEMA 14-50R plug.
It’s running the latest firmware (8.2.0) and ESP32 (4.1.3).
I am getting a “No Earth Ground” error when it attempts to start charging. I’m not smart enough to correct this but apparently has to do with the coil. Otherwise works great. Sold as is.
I saw this issue show up on my unit when I applied the 8.2.0 firmware. When I rolled it back to 7.1.3 it went away. You may want to give that a try before you give up on it.