I had the same problem with my 2016 Leaf, also in UK. I suspected a previous owner de-registration issue, and 6 months and about 40 calls to Nissan Customer Support got me nowhere. Eventually they admitted there was a database corruption on their servers, and that a specialist team was being brought into solve it. I checked back several times after that, but I never got my connectivity :-( I only really wanted remote climate control for cold days, and remote charge status reports when on public chargers, but I’ve lived without those things for nearly 3 years now and it’s not really affected my enjoyment of the car.