Zabbix Trigger Status Switching from PROBLEM to OK instantly?

[Ragnaxbl]

Were having a problem on our zabbix instance where sometimes a trigger will change from PROBLEM to OK instantly and the OK notification will not get sent.
Not sure whats causing this as the same trigger has fired before and both the PROBLEM and OK notifications were sent at the appropriate times.

i've attached a screenshot from the event history

any idea as to what causing this?

[teskistajer]

the info on screenshot is not enough we can not see what is the trigger so why it changes on an instant

Edit : if it is reporting about outgoing traffic which is low or high isnt it normal to trigger an instant cuz bandwidth traffic can change instantly ? i am new user too ,do i miss something