Fix? - Pi-Hole DHCP broke LAN access via OpenVPN on separate device

[25zerotwo]

Greetings all, I arrive here having looked at numerous guides and tried a few things already without success.

I run Pi-Hole on a Rasp PI and I also have a separate Rasp PI which has OpenVPN running on it, both locked down via firewalls to ensure only the OpenVPN is exposed to outside world.
VPN connection was working and giving access to internal LAN just fine until I enabled DHCP on the Pi-Hole (something I had to do due to Netgear router not supporting DNS on internal IP)

I am certain I need to bridge or forward the traffic between the eth0 and tun0 connections somehow, but as said every guide that I thought solved the issue, has failed to do so, also concede this is more an OpenVPN issue than Pi-hole, but hoping a bright mind has had this same issue here. Thanks in advance.

Expected Behaviour:

Connect to VPN from outside world, and remotely access CCTV on 192.168.0.141:9000

Actual Behaviour:

Unable to access any internal IP (including Pi-hole) from the VPN tunnel. I cannot ping any LAN side host from the Tun0 connection.
I can however ping from eth0 (on the Lan side) fine.

LAN settings

Pi-hole IP 192.168.0.53
OpenVPN 192.168.0.54
LAN IP range 192.168.0.0/24
Gateway 192.168.0.1
VPN Tun range 10.8.0.0/24

Debug Token:

https://tricorder.pi-hole.net/zz4nobllro!

[Tntdruid]

Did you set Listen on all interfaces, permit all origins?

[25zerotwo]

No, I don’t think that would work. The Pi-hole is only connected to the LAN via eth0.
That being said, I have had that enabled for some time, because it isn’t internet exposed and hence no reason not to. Issue persists in that state though.

[25zerotwo]

SOLVED

Found I had a static line written into my /etc/rc.local file

"iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to 192.168.0.28"

I had changed the IP of my PI to 192.168.0.54 and seeming that IP forwarding (as you would expect) was causing a problem...