Apex domains cannot have CNAME records.
Question and response
Question
dig consultisp.com.br. NS
Answer
consultisp.com.br. 5 NS ns1.consultisp.com.br.
consultisp.com.br. 5 NS ns2.consultisp.com.br.
Authority
The response has no authority records.
Additional
ns1.consultisp.com.br. 5 A 177.10.20.42
ns2.consultisp.com.br. 5 A 177.10.20.49
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0