vsftpd, restrict FTP user to specific folder

Question

On my Ubuntu 18.04 server I have created a FTP user (named ftphtm3) for which I want to restrict access to folder /var/www/html3

Here is what I have done so far:

1. created a FTP directory /var/ftp/ftphtm3 and bound it to /var/www/html3, mount --bind /var/www/html3 /var/ftp/ftphtm3

2. changed user's home directory: usermod -d /var/ftp/ftphtm3/ ftphtm3

3. in /etc/vsftpd.conf: chroot_local_user=YES, chroot_list_enable=YES

But then, when with filezilla as user ftphtm3, I land in /var/ftp/ftphtml3 BUT I can still go back to neighbours or parent directories (in fact I have access to all my server).

Do you have any idea what I have missed ?

Thank you

p.s: the steps for "restricting" the access come from this post but I would like if possible to avoid binding directories. I just ftphtm3 to land in /var/www/html3 and to only have access on it. That's it.