Steps to reproduce:

1. have no idea.

Result:

at some hosts this trigger always active, already for a month+.

agent restart, host reboot, etc didn't help.

Agent send all data to server as intended, even a ping status. So trigger have a info that host is up, but show it is down.

at most other hosts it triggering very often for a short time. 2-5min, usually not more than trigger time (5min). With default 30min it active for 30min.

I'm using only active checks.

It begins at 5.4 clean install. Same contunie at 6.0 clean install to. My older zabbix server 4.4-5.0 have no this issue.