Custom Audio Assets aren't packaged

Hi All
I’m using UE 4.24 and I’m developing my plugins with the Shooter Game demo provided by epic.
Now, in my project I have some custom audio which I put under the folder:
ShooterDemo/Content/Sounds/MyCustomSounds.
In the game editor, the audio files are correctly imported and play properly in both PIE and standalone.
However, when I try to pack the game my custom sound folder is always skipped in the final packed game, thus my custom audio files aren’t played anymore.
Before packaging, I always cook the project but this seems to be ineffective.
Doesn’t anybody have any clue of what’s happening ??

Cheers!