Apex domains cannot have CNAME records.
Question and response
Question
dig pontedigital.com.br. NS
Answer
pontedigital.com.br. 5 NS ns2.pontedigital.com.br.
pontedigital.com.br. 5 NS ns1.pontedigital.com.br.
Authority
The response has no authority records.
Additional
ns1.pontedigital.com.br. 5 A 170.80.48.26
ns2.pontedigital.com.br. 5 A 170.80.48.27
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0