When I do a reverse DNS query for the ip-address of pi-hole itself I do get a strange answer.
I use knot-resolver as my backend resolver and if I ask knot, I get "pi-hole.example.com."
But if I ask pi-hole I get "pi-hole.no_fqdn_available."
Where is that name coming from? And why?
I do not use pi-hole as my dhcp server, but knot will ask my dhcp server for reverse queries and get the correct answer.