I'm monitoring many machines, these machines (CentOS and Debian) have installed zabbix agent 1 and 2, but as the title says some of them won't appear on dashboard when disk space is critically low (90%).

I'm using "Linux filesystems by Zabbix agent active", a default Zabbix template and as you can see in the following screenshoot, the marked with a "X" is the one isn't working for some machines. However, the marked in green (Disk space is low 80%) works for any machine, even the problematic ones!

It doesn't matter the OS, I have this problem on CentOS and Debian machines and happens with the zabbix agent 1 and 2. That's all I've dismissed.

The strangest thing is that the trigger works for most of the machines, but in a few ones won't work...

Please help me, I need to fix this urgently because some machines ran out of space and I wasn't able to detect it on time.​

Example of a problematic machine:
As you can see it's 98% of disk space but zabbix only shows 80% alert on dashboard.​

Example of a working machine:

I dicovered in "Latest Data" and "Graphs" that the problematic hosts receive the data I want, but won't show it at the dashboard. Why? All hosts have the same items and triggers, no custom ones. I already tried to modify the dashboard and tried all options but didn't fix this.

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