Apex domains cannot have CNAME records.
Question and response
Question
dig issuetrak.com. NS
Answer
issuetrak.com. 5 NS ns-1875.awsdns-42.co.uk.
issuetrak.com. 5 NS ns-1230.awsdns-25.org.
issuetrak.com. 5 NS ns-381.awsdns-47.com.
issuetrak.com. 5 NS ns-849.awsdns-42.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0