eva.ns.cloudflare.com has no CNAME records.
Question and response
Question
dig eva.ns.cloudflare.com. NS
Answer
The response has no answer records.
Authority
cloudflare.com. 8 SOA ns3.cloudflare.com. dns.cloudflare.com. 2397006400 10000 2400 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0