Error: Your data directory is readable by other users

I have Nextcloud as a container in docker, with /data folder bound to
Docker is on Raspberry Pi 4B, Raspberry Pi OS, Debian 11.
HDD is an external Hard Drive, NTFS (in an Amazon basics drive SATA enclosure, if it matters).
In /etc/fstab it is mounted as: /dev/sda2 /media/filip/HDD ntfs defaults 0 0

I have done
sudo chown -R www-data:www-data /media/filip/HDD/nextcloud_data/data
sudo chmod 0770 /media/filip/HDD/nextcloud_data/data
and even (at GPT’s request :sweat_smile:)
sudo setfacl -R -m u:www-data:rwx,d:u:www-data:rwx /media/filip/HDD/nextcloud_data/data

But whatever I do it still remains:

# file: media/filip/HDD/nextcloud_data/data
# owner: root
# group: root

I’m new to Linux. Am I mounting the HDD wrong? Why can I not edit permissions or owner?

Thank you for your help,

I gave up and just added the
'check_data_directory_permissions' => false,
line in config.php .
Works ok now. Does that pose future problems or security risks?

I’m using the following access rights for the data directory:

find /nextcloud_data_path/ -type f -print0 | xargs -0 chmod 0640
find /nextcloud_data_path/ -type d -print0 | xargs -0 chmod 0750

just turn it off