ns1.ioflood.com has no CNAME records.
Question and response
Question
dig ns1.ioflood.com. NS
Answer
The response has no answer records.
Authority
ioflood.com. 1800 SOA candy.ns.cloudflare.com. dns.cloudflare.com. 2397983569 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0