kanc.firma.sofia.sk has no CNAME records.
Question and response
Question
dig kanc.firma.sofia.sk. NS
Answer
The response has no answer records.
Authority
sofia.sk. 3587 SOA hydrogen.ns.hetzner.com. dns.hetzner.com. 2026021701 86400 10800 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0