ns3.duxhub.com has no CNAME records.
Question and response
Question
dig ns3.duxhub.com. NS
Answer
The response has no answer records.
Authority
duxhub.com. 297 SOA ns1.mysecurecloudhost.com. servers.mysecurecloudhost.com. 2026022500 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0