My son (the tech wizz) reckons the MMI system will have been updated remotely. I would have though my 2016 A6 would have been before the technology?
Audi offers remote firmware updates for certain models via over-the-air (OTA) technology. This means that you can update your car's software without needing to visit a dealership, according to Audi UK
So glad I found this thread. Like so many other I was loosing the plot with frustration over the loss of DAB. I am sure mine a dropped a couple of times before the end of March though.