Steps to reproduce:

1. create an atuto registration rule to link to a template...
2. set HostMetadataItem on agents - by custom script to detect a service on os for expample detect php-fpm service

Result:
at first its worked and host linked to the php-fpm template
but i unlink and clear the template from that host and then autoregistration not worked again i restart the zabbix-agent service but it dosent work