Steps to reproduce:

1. Create UserParameter for Zabbix Agent2
2. Test the item with command zabbix_agent2 -t

root@zbx50:~# grep ^UserP* /etc/zabbix/zabbix_agent2.conf
UserParameter=test.test,echo "test output"

Result:
The item fails "Unknown metric" when testing with agent, the user parameters are not initialized for testing. It works with zabbix_get and when server gets the item.

root@zbx50:~# zabbix_agent2 -t test.test
test.test [m|ZBX_NOTSUPPORTED] [Unknown metric test.test]
root@zbx50:~# zabbix_get -s127.0.0.1 -p 10040 -ktest.test
test output

Expected:
That it would return the key in correct format when testing