zabbix.online.net.br has no NS records.
NS records for this zone are defined at online.net.br.
NS records for this zone are defined at online.net.br.
Question and response
Question
dig zabbix.online.net.br. NS
Answer
The response has no answer records.
Authority
online.net.br. 10 SOA ns01.online.net.br. noc\@online.net.br. 202412946 3600 1800 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0