Apex domains cannot have CNAME records.
Question and response
Question
dig zyravento.com. NS
Answer
zyravento.com. 2 NS ns-421.awsdns-52.com.
zyravento.com. 2 NS ns-1926.awsdns-48.co.uk.
zyravento.com. 2 NS ns-1811.awsdns-34.co.uk.
zyravento.com. 2 NS ns-438.awsdns-54.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0