Steps to reproduce

Link LLD-item-is-not-discovered-anymore.xml template to host "Zabbix server" and reload configuration cache:

zabbix_server -R config_cache_reload

Send two traps:

zabbix_sender -z 127.0.0.1 -s "Zabbix server" -k lld.trap -o '{"data":[{"{#VAR}":"one"},{"{#VAR}":"two"}]}'
zabbix_sender -z 127.0.0.1 -s "Zabbix server" -k lld.trap -o '{"data":[{"{#VAR}":"one"},{"{#VAR}":"three"}]}'

Go to Zabbix server items and filter application "var". Observe if one of the items is not discovered anymore:

Let's try to identify this via API by using selectItemDiscovery query:

{
	"jsonrpc": "2.0",
	"method": "item.get",
	"params": {

		"selectItemDiscovery": "query",
		"search": {
			"key_": "key"
		},

		"output": "extend",
		"hostids": "10084",
		"sortfield": "name"

	},
	"auth": "e8e040ac9dc043aa6045acd180703061",
	"id": 1
}

The following response.json shows 3 items but the array itemDiscovery[] is empty.

Expected

Based on the documentation page itemDiscovery must show attributes:

• lastcheck - (timestamp) time when the item was last discovered;
• ts_delete - (timestamp) time when an item that is no longer discovered will be deleted.

.. and more