I can't access the admin page of Pi-hole using the dns name

[PromoFaux]

Sorry, yeah I misread the debug log.

Looks like your IPV6 address has changed since you first installed pi-hole.. the one in /etc/pihole/setupVars.conf is different to the actual IPV6.

If Pi-hole is handing out the one in setupVars.conf to your clients, then they're going to have a bad time resolving domains...

Please see this thread for some information about that:

Use IPv6 ULA addresses for Pi-hole

Many users have reported that frequently changing IPv6 addresses cause page load to be slow or even prevent from working at all. The issues can be fixed by updating the IPv6 address in /etc/pihole/setupVars.conf followed by a run of pihole -g. However, this solution turns out to be very inconvenient since it might be necessary to change the IPv6 address on a regular basis (maybe even multiple times a day). An alternative approach we are currently looking into is the usage of ULA addresses which…