History: I have gone over my internet limit and the wlan doenst work...
So I switched to the offline mode and start shuffle play (start screen top right).
The problem is that the shuffle ignore the offline mode and try to download the music.
So I have to add every mp3 on my mobile and start playing with the shuffle sort order (player view right bottom).
I'm not shur if its a bug or maybe a missing use case or a missunerstanding of mine.