Apex domains cannot have CNAME records.
Question and response
Question
dig jcwdns.net. NS
Answer
jcwdns.net. 4 NS linus.ns.1-grid.com.
jcwdns.net. 4 NS linus.ns.1-grid.co.za.
jcwdns.net. 4 NS linus.ns.1-grid.co.uk.
jcwdns.net. 4 NS linus.ns.1-grid.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0