EVSE Red and Green lights flashing after charge

Best to consult Nissan Leaf owner's manual. The red flashing light on Toyota OEM EVSE means an Error warning, but that could be totally different for different EVSE.

 

I found this in the 2018 Leaf manual.
The double circle means it's blinking.

 

Among other faults, that flashing red light can me a ground fault issue. However, I discovered that it can occur when plugged into a GFCI-protected outlet with a failed GFCI. In other words, it can be the outlet's fault and there is nothing wrong with the EVSE.

(I discovered this when using an outlet at a friend's house to charge my Prime. My friend later told me was "squirrely" and had been causing him problems. It was an exterior outlet on the wall of his house and he said that it sometimes "acted up" after a heavy rain. He subsequently had it replaced and rewired by his electrician which resolved his problems.)

This reminds me of issues I have seen where multiple cascaded GFCI devices have caused problems. For example, when a GFCI outlet is added downstream of another GFCI outlet which is already protecting the circuit. Maybe one of the electricians here can explain why this can happen.)

Anyway, the indicated fault may not be in the EVSE so it's worth trying a completely different outlet and circuit and seeing if the problem is reproducible.

 

The way I read how they work is that they measure the difference in current flowing into and out of the GFCI. If they don't match, it trips and opens the circuit. They also look for current between gound and neutral. There is no NEC prohibition against having more than one interrupter on a circuit afaik. But multiple GFCIs on the same circuit is a wast of money. And, if one of them is tripping the other one, then I would think there would be a problem with one or the other device. Here's a video that's probably TMI and it's dry as dust, but it does show how they actually work. They are even more sophisticated than I thought.

The text version is here.
Teardown: Leviton ground fault circuit interrupter - Power Electronic Tips