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