Apex domains cannot have CNAME records.
Question and response
Question
dig zenvintor.com. NS
Answer
zenvintor.com. 5 NS ns-2003.awsdns-58.co.uk.
zenvintor.com. 5 NS ns-724.awsdns-26.net.
zenvintor.com. 5 NS ns-1237.awsdns-26.org.
zenvintor.com. 5 NS ns-1395.awsdns-46.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0