library doesn't show files

I mounted NAS outside volumio using this guidelines mounting-nas-outside-volumio-t2126.html#p19860
NAS is mounted successfully, however volumio doesn’t list any audio file in library after update library
Strange things, when I search certain songs, volumio can find it and list out the file
I have made sure files have correct read permission, chmod -R ugo+r /mnt/NAS/XXXX(shared folder)
Any idea what could be wrong?

Which version of Volumio?

Why mount it outside of Volumio?

problem solved
i found out, network media has to be linked to “…/NAS” as link name
if link to other name, it won’t list library files