There's a lot of cheap Chinese cable being used by ROLEC and several other venders. You will need to replace the cable with decent European manufactured cable to properly cure the problem.I have a wallbox tethered charger. Works OK for my needs.
The cable is driving me insane though, its so thick that it won't coil up easily. It has a "memory" and springs apart when you try to coil it neatly on the holder. We also have pebble dash render on the house (Scotland) and the stupid cable rubs against it and damages it because it wont sit straight when looped around the holder.
First World problem I know, but is there a more flexible, pliable cable I can replace it with?
The cable that EcoHarmony supply is decent quality, I've had mine since 2017. ( 6mm2 - 32A).