I spoke to BMW today and they mentioned a control unit recall on the charging side. So I have booked it in, if this cures it then hooray.
If that fails then they said that they will scan the car to see what the issue is.
I mentioned that the lock mechanism on the charger side wouldn't lock, but that wasn't covered under the recall.
I will see which parts are under the recall and update as I think this would be quite useful.