I have pihole-ftl behind Wireguard on Ubuntu vps. I connect to server remotely from everywhere on either phone or laptop. So far it's running fine. The Web UI has only 1 issue in diagnosis but I do have a few issues in debug log. My servers ipv6 address is resolving which it shouldn't. I have the Wireguard private ipv4, ipv6 interface addresses for pihole addresses. So, why is that address still being used and how to properly configure Ubuntu /etc/resolving.conf and Wireguard dns settings in wg0.conf file. I will write and write till I get a headache so if this is too much info let me know. Thanks for spending your time and effort on this. Totally appreciated.
If you are referring to your server's domain here:
Pi-hole has absolutely no influence on public DNS resolution.
Public domains are expected to be resolved to IP addresses.
That seems like an OS level or Wireguard configuration issue.
In general, if you would be running your installation on a publically accessible server, you want to make sure its properly firewalled - in particular, DNS/port 53 access should not be publically accessible at all.
EDIT:
From one of your other posts, your debug log shows your Pi-hole host machine to receive DNS traffic from public IP addresses.
This indicates that your router's and/or your Pi-hole machine's firewalls are allowing public DNS/port53 access.
You are just on step away of running an open resolver, posing a potential threat for all Internet users, e.g. by serving as a multiplier in a DNS Amplification attack .
If this is a cloud-based Pi-hole installation, you should close port 53/DNS for public access on your server.