miimura wrote:
As above, I would definitely look at all the wiring between the EVSE and the breaker.
Every connection should be checked for discoloration and tightness. If you still can't find anything wrong, disconnect the breaker, remove it from the panel and check the connection between the breaker and the panel. While it's disconnected, check the resistance between each hot wire and the other and between each hot wire and ground. There should be no measurable resistance between any of them, ie. open circuit.
I would suggest doing the same for the connections inside the EVSE and the charging handle. I just had one of my J1772 plugs (of about the same age) fail. The breaker had blown. It was badly discolored inside, and the insulation on the wires was burnt away.

I replaced it with, ironically, a Leviton plug and cable assembly.