Thank you @Paul - iBassoYou can try a rescan of the card and also check the tagging.
rescan works, at least they are put in the unkown folder.
I need to advice for a bug: DSD256 are not read. Both in standard android mode and in mango mode.
Sometimes starts but it is mute or simply, clicking on play, nothing happens.
The same DSD256 files are perfectly reproduced by my AR-M2 (even if this player is given for DSD64/128).
Hope you can solve since one of the reason I took this player is because is one of the few (maybe the only?) is given on the paper for the official support of DSD512...