Info about DAB+
What Is The Difference Between DAB+ and DAB?
DAB+ is a further development of the DAB standard, thus assumes all functions of DAB, but offers additional benefits. The technical difference is the type of audio coding, ie the two standards use different methods for the preparation before and after the transfer of data. While DAB uses MPEG-1 Layer-2, DAB MPEG-4 HE-AAC v2, the most efficient audio compression used worldwide.
Also found this on another forum:
"It seems most of D1 national has now gone to Dab+ which means the audio on the channels is now He-aacv2. This unfortunately means head units with old chipsets cannot decode the new audio. Our Audi A1 is affected but not the A3 (both 2018). The A3 can decode the new audio so is ok. There is a chance audi dealers could charge £140 if you take the car for inspection when in fact there is no fault. The problem is D1 going to Dab+. Have just contacted Bauer and they have confirmed the switchover of the channels. Other Audi models affected could be Q3 2017 or anything before 2018 with a head unit that has cd sd dab combined which is installed in the dash rather than separate units for dab etc."