ns1.donweb.com has no CNAME records.
Question and response
Question
dig ns1.donweb.com. NS
Answer
The response has no answer records.
Authority
donweb.com. 1800 SOA carol.ns.cloudflare.com. dns.cloudflare.com. 2397336165 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0