ns1.certto.com.br has no CNAME records.
Question and response
Question
dig ns1.certto.com.br. NS
Answer
The response has no answer records.
Authority
certto.com.br. 258 SOA ns1.certto.com.br. support.certto.com.br. 2026013000 43200 3600 1209600 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0