Permission

hi,
i have a problem with database.
My hdd is mount on pi4 wich has lms with ubuntu 20.4.
First scan was ok.
But i can't see files i add after.
and new scan gives nothing, the lms database doesn't see it.

i tried to check permission with ls -dl /mnt/maxtor/musique
drwxrwxr-x 179 ubuntu lms 20480 Aug 23 06:44 /mnt/maxtor/musique

well ok
if i use sudo chown -R ubuntu:lms /mnt/maxtor/musique
my new folder appears in lms database, and i can scan with lms, but i have to do this each time i add a new folder...

Any ideas?