Apex domains cannot have CNAME records.
Question and response
Question
dig jobs-monster.com. NS
Answer
jobs-monster.com. 5 NS ns-1349.awsdns-40.org.
jobs-monster.com. 5 NS ns-1667.awsdns-16.co.uk.
jobs-monster.com. 5 NS ns-1714.awsdns-22.co.uk.
jobs-monster.com. 5 NS ns-1140.awsdns-14.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0