Apex domains cannot have CNAME records.
Question and response
Question
dig madrinet.net. NS
Answer
madrinet.net. 5 NS ns-564.awsdns-06.net.
madrinet.net. 5 NS ns-895.awsdns-47.net.
madrinet.net. 5 NS ns-80.awsdns-10.com.
madrinet.net. 5 NS ns-699.awsdns-23.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0