Web interface not reachable through IPsec VPN (using docker container)

[eggbean]

I'm not new to Pi-Hole, but I've not used it on cloud instances before.

I can't get the Pi-Hole web interface through IPsec VPN (DNS works). The identical setup works fine on another cloud instance through a public IP address through the public internet.

Setup: Two subnets on Oracle Cloud for testing.

docker run --rm -d \
    --name pihole \
    -p 53:53/tcp -p 53:53/udp \
    -p 80:80 \
    -e TZ="Europe/London" \
    -e WEBPASSWORD='admin' \
    -v "${PIHOLE_BASE}/etc-pihole:/etc/pihole" \
    -v "${PIHOLE_BASE}/etc-dnsmasq.d:/etc/dnsmasq.d" \
    --dns=127.0.0.1 \
    --hostname pi.hole \
    -e VIRTUAL_HOST="$(hostname -s)" \
    -e PROXY_LOCATION="$(hostname -s)" \
    -e FTLCONF_LOCAL_IPV4="$(hostname --ip-address)" \
    pihole/pihole:latest

Public subnet running Pi-Hole in docker container on Oracle Linux. Firewall - open all ports and protocols to my home static public IP address. Everything works fine. DNS and web interface.

Private subnet. Exactly the same as above, but in a private subnet accessible through IPsec VPN. No response from web page. DNS requests work fine.

I thought it was an issue with the VPN until I typed http://10.10.1.10/admin/loginn.php instead of http://10.10.1.10/admin/login.php and got a 404 page not found from the lighttp web server.

Also, I can see the web interface through the terminal lynx browser and I can curl http://10.10.1.10/admin/login.php and see it too.

I haven't got much experience with Oracle Linux (essentially CentOS), which has SELinux enabled and has an iptables firewall. I mostly use Debian or CentOS with these disabled, but I don't want to do that anymore (and it doesn't seem to help when I do).

Any ideas?

[eggbean]

I have added the :z to the ends of the path for SELinux, which is recommended in the README.md

-v "${PIHOLE_BASE}/etc-pihole:/etc/pihole:z" \
-v "${PIHOLE_BASE}/etc-dnsmasq.d:/etc/dnsmasq.d:z" \

...however, I still cannot access the web interface through the VPN.

[eggbean]

I have now tried with an Ubuntu instance, and exactly the same occurs. So at least now I know that it has nothing to do with SELinux or any incompatibility with RHEL-based distros as the docker host.