ns2.systemdns.com has no CNAME records.
Question and response
Question
dig ns2.systemdns.com. NS
Answer
The response has no answer records.
Authority
systemdns.com. 180 SOA ns1.tucows.com. hostmaster.systemdns.com. 1771767022 10800 3600 2592000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0