Tag binding is not firing automatically

I have made a timer script to simulate tags that are similar to MQTT engine, such that it will update the timestamp in 10 sec now in view I have made a message with label that after 30 sec if timestamp is not updating then it will make visible the message "Data is stale not fresh", but when I am stoping the timer script the value inside the visiblity (edit binding) is changing but it is not coming to the component only if I press ok or apply it will get updated in the component visiblity.

This is my timer script:

on yellow marked is timestamp that I am making visiblity script.

Below is my visiblity on embeded component.

Also below is my timestamp difference calculation script that I am using in visiblity component: