Sorry, I didn’t mention my DNS config. I have a split DNS setup. public.domain.co.uk resolves to a WAN IP on WAN-side and a LAN IP on LAN-side, both connecting to the reverse proxy.
It spits out the my.internal.domain.co.uk hostname, just the once, which resolves to the private IP and should only be used by the Apache reverse proxy.
Your comment about the XML config file sounds promising:
I shall check the XML file out to see if the internal DNS name is in there somehow.
Everything else is working inside and out so far and I don’t want to take steps backwards just yet.
Many thanks for the lightening fast response. <3