cannot hear emulationstation background music anymore

[Jeero]

Hello, I have a problem to play music while I am on the recalbox interface (or rather when I am on emulationstation),

It happened when I configured the Roms folder to be used on my NAS, I guess there must be a link .... but I don't know which one because I asked to share only the Roms folder and nothing else.

I use recalbox 9 and a Raspberry 3b.

Oh yes and I also added songs in the music folder (the folder that is on the SD card of the Raspberry) I have the notifications on the screen when it starts the music, with the names of the songs I added, except that there is no sound.
The sound of the intro of Recalbox at startup I hear it well, the music in the games too.

I did some research on the net (and on the forum), but I didn't find anything about this, if someone would have some ideas of resolution... thanks !