Apex domains cannot have CNAME records.
Question and response
Question
dig allinmedia.com.br. NS
Answer
allinmedia.com.br. 5 NS nsmaster2.auinmeio.com.br.
allinmedia.com.br. 5 NS ns2.auinmeio.com.br.
allinmedia.com.br. 5 NS ns3.auinmeio.com.br.
allinmedia.com.br. 5 NS nsmaster.auinmeio.com.br.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0