Apex domains cannot have CNAME records.
Question and response
Question
dig myxyzzy.com. NS
Answer
myxyzzy.com. 5 NS ns-987.awsdns-59.net.
myxyzzy.com. 5 NS ns-990.awsdns-59.net.
myxyzzy.com. 5 NS ns-1289.awsdns-33.org.
myxyzzy.com. 5 NS ns-1729.awsdns-24.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0