dexter.ns.servercow.net has no CNAME records.
Question and response
Question
dig dexter.ns.servercow.net. NS
Answer
The response has no answer records.
Authority
servercow.net. 60 SOA dns200.anycast.me. tech.ovh.net. 2026022100 86400 3600 3600000 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0