[PROBLEM] One folder empty view

[pegaso]

Run the command below to check the directory and file permissions in the file system. The directory permissions should contain the Execute permission for example drwxr-xr-x and the file permissions should contain the Read permission for example -rw-r--r--. Owner should be root:root. 

Code:

ls -al "/mnt/NAS/Musica/FOLDER_NAME"

Check the metadata for a given file

Code:

mediainfo "/mnt/NAS/Musica/FOLDER_NAME/FILE_NAME"

I checked it. There's no problem with permission.
I have root root drwxrwxrwx.
I've  also checked by WinSCP all files in this problematic folder have properties: owner 501, group 500, owner RWX, group RWX, others RWX; octal 0777 (the same value as others non-problematic folders). It looks like a problem in MoodeAudio
This folder from my NAS  is visible and fully usable when I use: foobar2000 on my comp (win10), Volumio on rpi 3B+ and M.A.L.P (mpd on android).