Why log item show difference time output with the log file

[bab]

I have created a log item (zabbix agnet active) such as follow to find a string (Connection reset) in my log

log["/usr/local/wildflySubSystem/wildfly-13-Inquiry/standalone/log/sayad.log","Connection reset",,,skip,\0]

There is an strange issue . It is showing last "Connection reset" at 20:34 in the history of that item but when open the log file it is showing "last Connection reset" at 19:57
interval is 10s

What is the issue ?
Also the time of that host and zabbix server is ok

[Blevar]

If there is a high CPU or a network load then the agent might delay pushing data. try ```zabbix_get -s <host_ip> -k agent.ping``` and see how much time you need to get a response