Why is this NODATA trigger firing?

[Pavel382]

Hello!
Zabbix server 5.0.21

I have a linux host without zabbix agent which is monitored via snmp. I created nodata trigger to alert me if no data is received about disk partition (it is a NFS volume which sometimes is unavailable due to network issues).
However, nodata trigger is firing when this partition is online and data about it is successfully received by zabbix server.

Trigger expression:

 {Linux-YT-90:hrStorageSize[/mnt/backup].nodata(300)}=1

Latest data for this item constantly shows 488.37 Munits (which is perfectly normal)

Why is this nodata trigger firing?

Thank you.

[Pavel382]

It turned out item was queried every hour, so after matching nodata trigger period with item update interval trigger started working as expected.
Sorry for the inconvenience.

[Pavel382]

It turned out item was queried every hour, so after matching nodata trigger period with item update interval trigger started working as expected.
Sorry for the inconvenience.