Audio not fading on comand ntg2.5

[hercules]

I just finished to swap my NTG2 to NTG2.5 on my w203 has been properly coded and had the latest software installed.
But I noticed that the audio is not fading when the navigation is active.
Is this a bug ?

 

[Diesel Benz]

I assume it is the same as with some other Comand models, audio fading disappeared at some SW revision and reappeared later on. It is not a bug but a feature, otherwise MB would fix it for free.