Apex domains cannot have CNAME records.
Question and response
Question
dig b01fcd80-idc.po.dinpro.com.br. NS
Answer
b01fcd80-idc.po.dinpro.com.br. 5 NS ns2.dnzdns.com.
b01fcd80-idc.po.dinpro.com.br. 5 NS ns1.dnzdns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0