how to check if zabbix agent 'correctly' send Host MetaData?

[EvilEugene]

Hello all.
last night, I experienced strange situation.
most of my servers are running on the cloud, but some of servers are physical machine.
and here's the problem : cloud servers are automatically registered by discovery rule and 'auto registration' action, but NOT physical machines

after some hours of search, I removed 'host MetaData like' option from auto registration rule, and finally, zabbix server added my physical machines...

so I suspect that zabbix agent 'may be' not send host MetaData, but I couldn't find any workround for this.

Is there any method to check if zabbix agent correctly send HostMetaData?

thanks for help

PS:
Of course I added host metadata into zabbix_agent.conf like this :

# Mandatory: no
# Default:
HostnameItem=system.hostname

### Option: HostMetadata
#	Optional parameter that defines host metadata.
#	Host metadata is used at host auto-registration process.
#	An agent will issue an error and not start if the value is over limit of 255 characters.
#	If not defined, value will be acquired from HostMetadataItem.
#
# Mandatory: no
# Range: 0-255 characters
# Default:
HostMetadata=gf365live