Apex domains cannot have CNAME records.
Question and response
Question
dig sitexo.com. NS
Answer
sitexo.com. 2 NS ns-270.awsdns-33.com.
sitexo.com. 2 NS ns-754.awsdns-30.net.
sitexo.com. 2 NS ns-1128.awsdns-13.org.
sitexo.com. 2 NS ns-2010.awsdns-59.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0