Apex domains cannot have CNAME records.
Question and response
Question
dig suport-pj-empresas.com. NS
Answer
suport-pj-empresas.com. 3 NS ns1.dominios.uol.com.br.
suport-pj-empresas.com. 3 NS ns2.dominios.uol.com.br.
suport-pj-empresas.com. 3 NS ns3.dominios.uol.com.br.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0