Apex domains cannot have CNAME records.
Question and response
Question
dig banqi.com.br. NS
Answer
banqi.com.br. 5 NS a24-67.akam.net.
banqi.com.br. 5 NS a9-65.akam.net.
banqi.com.br. 5 NS a10-65.akam.net.
banqi.com.br. 5 NS a1-74.akam.net.
banqi.com.br. 5 NS a5-64.akam.net.
banqi.com.br. 5 NS a12-66.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0