Steps to reproduce:

1. IFRs Tested:
   1. Kubernetes with PostgreSQL
   2. AWS with MySQL ( RDS ): 2 ZabbixServer/Frontend.
   3. On both IFR, tested with zabbix 5.0.2 and 5.0.3
2. Create a ITEM type "zabbix_agent" in a host with interval "1minute", example key:

1. 1. net.tcp.listen[7777]
2. Create a trigger that check this new item and configure "PROBLEM event generation mode" with "Single" type.
3. When the trigger is on Problem, you will see that is showing multiple times.

Result:

Item screenshot

Problem screenshot

Expected:

Only one Event should show in Problem dashboard. This functionality is like "Multiple" type of trigger.

I tested the same with Zabbix4.0, and Zabbix3.0 and work correctly.

I created too a post in forum " Zabbix Troubleshooting and Problems".

https://www.zabbix.com/forum/zabbix-troubleshooting-and-problems/407725-triggers-with-single-problem-event-generation-mode-show-multiple-times-zabbix-5-0