What does a EV charging point actually do?

I have bought a 2nd hand Nissan leaf and have been happily charging it slowly from a 13A socket (fed by solar panels) for 6 months using the "granny lead" that comes with the car.

Yesterday, when I turned it on, the READY and CHARGE light flashed about once per second, as did the lights on the dashboard, and there was a click each time from the unit. The manual does not list this combination as indicative of anything.

This lead me to wonder what the "charging unit" actually does, It lists its input and output as 250V ac so it clearly is not a transformer/ rectifier. If it is a protective relay measuring neutral earth voltage, then maybe the ON / OFF is caused by something happening to the voltage in the house?

I have not found any information on the internet as to what is inside these units.