Steps to reproduce:
- Start monitoring "many" hosts for issues (>50?)
- Trigger an alert on all hosts somehow
- Navigate to overview page, clear all filters.
Only some triggered alerts are seen.
See screenshots with full problem list, overview missing triggers and overview with filter restricting number of hosts and showing more triggers.
Expect to see the alerts for all hosts
Adding > 50 hosts to the filtered hostgroup starts to remove a host from the overview page.
Editing file /usr/share/zabbix/include/defines.inc.php
// Applied to tables with variable count of columns. Columns above this limit will be truncated.
Increasing that number to > host count seems to bypass the problem.
Similar issues on forum with overview page https://www.zabbix.com/forum/zabbix-troubleshooting-and-problems/403187-alerts-hidden-on-overview-page