Apex domains cannot have CNAME records.
Question and response
Question
dig myvan.descartes.com. NS
Answer
myvan.descartes.com. 5 NS ns-1304.awsdns-35.org.
myvan.descartes.com. 5 NS ns-807.awsdns-36.net.
myvan.descartes.com. 5 NS ns-432.awsdns-54.com.
myvan.descartes.com. 5 NS ns-1990.awsdns-56.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0