Apex domains cannot have CNAME records.
Question and response
Question
dig zyventrixa.com. NS
Answer
zyventrixa.com. 5 NS ns-1001.awsdns-61.net.
zyventrixa.com. 5 NS ns-1567.awsdns-03.co.uk.
zyventrixa.com. 5 NS ns-240.awsdns-30.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0