Lost all Bluetooth connections

Earlier this week, my D4 lost all the Bluetooth connections. No phones/tablets (I have 4 paired) were listed, it was empty.

Later in the day, when I used the car all the connections reappeared.

Today, I was driving the wife's Evoque, same thing happened, the Blutooth paired list was empty. It also wouldn't respond to destination inputs to the sat nav. It just froze when entering an address. I didn't notice if the D4 had this issue too as I was only doing a short journey.

As it happens, the Evoque was in for service, so I asked them to look at the issue. They confirmed a problem and said it needs a full software reload, which could take 2-3 hours and may "brick" the car (they have had this issue before) so suggested I book the car in for another day with a courtesy car for two days "just in case"..!

Has anyone else seen anything similar (the loss of Bluetooth connections, not the software bricking issue)..?

cheers

simon