Apex domains cannot have CNAME records.
Question and response
Question
dig main.cyberneticos.com. NS
Answer
main.cyberneticos.com. 2 NS ns1main.cyberneticos.com.
main.cyberneticos.com. 2 NS ns2main.cyberneticos.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0