QNAP Container Station PHP permissions error on Settings page

Hi,

I've recently installed the Pi-hole docker image through Contatiner Station on my QNAP NAS and everything installs fine and I can access the admin home page without issue but I'm getting the following error message when I navigate to the settings page:

There was a problem applying your settings.
Debugging information:
PHP error (2): parse_ini_file(/etc/pihole/setupVars.conf): failed to open stream: Permission denied in /var/www/html/admin/settings.php:12

If this helps. I get the following error if I navigate to the web root:
[ERROR] File not found: /etc/pihole/setupVars.conf

I've searched and read a couple of articles on this forum and on Reddit and this one seems most relevant but hasn't solved my problem:

I have mapped container folders pihole and dnsmasq.d to folders on the NAS and set full permissions on those folders including full guest permissions but this has not solved the problem.

I haven't done anything from the command line but I can SSH into the NAS if needed.

Please can you help diagnose and resolve this?

Many thanks.

Im having same issue.
Any updates on how you have solved it ?

By the way i have ssh'd to NAS and checked if there's permissions for acces to this file.
It is 777 which means that anyone can read and write there.

I didn't manage to solve this so I gave up and used a Linux LXC Ubuntu VM to host PiHole.

Bit of a shame as the VM approach is a bit overkill but it works.