Apex domains cannot have CNAME records.
Question and response
Question
dig mojohelpdesk.com. NS
Answer
mojohelpdesk.com. 1 NS ns-1614.awsdns-09.co.uk.
mojohelpdesk.com. 1 NS ns-769.awsdns-32.net.
mojohelpdesk.com. 1 NS ns-42.awsdns-05.com.
mojohelpdesk.com. 1 NS ns-1390.awsdns-45.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0