Action by remote command executed too much in 1 min

[dannyc]

I setup two "Action" under configuration. One is send mail and one is execute a script.
Most of them are using default value and function.

When trigger alert, i dont know why my script was executed more than 100 times in that 2 mins but email only one.
In Report > Action Log, it shows more than 100 times of script executed.
i checked "duration" value is same,
"default operation step duration" :1h
in operations > Operation detail > Step duration : 0

does any have any idea about it?

Zabbix version is 4.0.