Steps to reproduce:
- Create a host with Agent interface
- Create an item with "Zabbix agent (active)" type
- Wait until some data appears in Monitoring -> Latest data
- Observe host's availability in Configuration -> Hosts
Availability icon is gray which indicates that host's status is unknown (as per https://www.zabbix.com/documentation/current/manual/web_interface/frontend_sections/configuration/hosts). Though, documentation doesn't state that host status is unknown when only active items are being monitored.
Either availability icon should be green (if data arrives), or documentation should state that host status is unknown when only active items are being monitored on the host.