Annnnnnyyywayyy..... back on topic.
I have an ev charger in my garage, which is some 60+ metres from the house.
It's a 7kw charge unit for my Nissan LEAF, the garage is cabled in 16mm SWA, and I opted to make the garage TT, so it has its own rod.
I remember being told that the EV chargers are sensitive to earth impedance, and from memory the loop impedance of my garage earth is about 80ohms
Anyway, the charger worked fine for a good few months, then it would error when connecting to the car on a few occasions, I've since installed a second rod, halving the impedance and I've not had a problem since.
Anecdotal I know, but from my experience it would appear that indeed they are a bit picky about the earth situation.
Cheers
Dan