My prior interaction with this forum has been about similar issues, but I have no idea on how to solve it this time.
I am again using Zentyal, but with DNS and DHCP not installed, expecting those to be handled by Pi-hole.
I seem to have a mysterious, and possibly automatically assigned IP address for the LAN interface that shows upon running a debug.
DHCP seems to be working, but DNS between my machine and Pi-hole does not. DNSmasq is not running, but th webui says all is fine. It doesn't seem to start on boot, and there I am sure (unlike last time) there is no other DNS server.
Right now, it is unreachable by the WAN IP, and I am connecting on that side to post this thread. LAN side, over SSH I can ping Google, so the machine seems to be configured to talk over that interface.
There are some IPv6 issues, but I think I can ignore those for now. Zentyal disables IPv6 as it cannot deal with it in this release.
With FTLDNS, dnsmasq is not required (or desired) to be running, as pihole-FTL does the work previously done by dnsmasq. The lines from your debug log below are normal:
*** [ DIAGNOSING ]: Pi-hole processes
[✗] dnsmasq daemon is inactive
*** [ DIAGNOSING ]: Ports in use
...
*:53 pihole-FTL (IPv4)
*:53 pihole-FTL (IPv6)
127.0.0.1:4711 pihole-FTL (IPv4)
From your debug log, the Pi-Hole is working properly. The lack of connectivity is likely due to a setting on either your router or the client(s).
*** [ DIAGNOSING ]: Name resolution (IPv4) using a random blocked domain and a known ad-serving domain
[✓] static.kameleoon.com is 0.0.0.0 via localhost (127.0.0.1)
[✓] static.kameleoon.com is 0.0.0.0 via Pi-hole (172.16.0.1)
[✓] doubleclick.com is 216.58.201.14 via a remote, public DNS server (8.8.8.8)
I don't use Zentyal and am not familiar with its behavior, but why would you expect your Pi-Hole to reachable from the WAN side of your network?