Apex domains cannot have CNAME records.
Question and response
Question
dig zynoventrix.com. NS
Answer
zynoventrix.com. 5 NS ns-971.awsdns-57.net.
zynoventrix.com. 5 NS ns-1719.awsdns-22.co.uk.
zynoventrix.com. 5 NS ns-1974.awsdns-54.co.uk.
zynoventrix.com. 5 NS ns-573.awsdns-07.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0