Apex domains cannot have CNAME records.
Question and response
Question
dig jujung.com. NS
Answer
jujung.com. 5 NS ns-1940.awsdns-50.co.uk.
jujung.com. 5 NS ns-1976.awsdns-55.co.uk.
jujung.com. 5 NS ns-122.awsdns-15.com.
jujung.com. 5 NS ns-1489.awsdns-58.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0