Apex domains cannot have CNAME records.
Question and response
Question
dig grupogesterec.com. NS
Answer
grupogesterec.com. 5 NS ns-1624.awsdns-11.co.uk.
grupogesterec.com. 5 NS ns-233.awsdns-29.com.
grupogesterec.com. 5 NS ns-371.awsdns-46.com.
grupogesterec.com. 5 NS ns-442.awsdns-55.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0