Audi A6 with Apple Iphone

Hi

I have a 2016 Audi A6 with a geniune Audi USB connection cable in the center armrest. The USB connection and the cigarette lighter point are not seen when I plug my phone in to charge and won't charge the Iphone. I have tried another Iphone and it is the same. A Samsung phone and other items all work fine and charge OK form both points. FYI, the Iphone charges fine everywhere else. I can only think it is something to do with the Audi voltage. Has anybody got the same issue? Do I need a dedicated cable with the Iphone connection?

Thanks
Andy

Thanks for the replies, I will try a new connector. Typical Audi, my phone charges in every other car from the USB or power socket. I guess their cars are sooo cheap they need to make their money somewhere...