• Zabbix 5.0 to 7.0 manual description

  Note that the Zabbix server (or proxy) always collects data regardless of the maintenance type (including "no data" maintenance). The data is later ignored by the server if 'no data collection' is set.

https://www.zabbix.com/documentation/5.0/en/manual/maintenance
https://www.zabbix.com/documentation/6.0/en/manual/maintenance
https://www.zabbix.com/documentation/7.0/en/manual/maintenance

if "no data collection" is selected, the monitoring data will be discarded for the following monitoring:

• Active checks of Zabbix server
• Monitoring via Zabbix proxy

However, passive monitoring will not perform monitoring if the status is "no data collection" during maintenance, as determined by the DCin_maintenance_without_data_collection function.