The advanced script only runs when the activity creates a NEW task. Since they are already existing, you need to put a condition in advance of the task activities to check for tasks and update them and then bypass the task activities.
As you can see in my example below, before the creation of tasks I put a If condition that checks for existing tasks and if found it updates the description and returns Yes there are tasks. If none are found then it branches to the task activities. Both go to the "next activity after tasks" so whatever activities you have after the tasks.
Here is the script in the If activity:
answer = hasTasks();
function hasTasks() {
var changeTask = new GlideRecord("change_task");
changeTask.addQuery("change_request", current.sys_id);
changeTask.query();
if (changeTask.hasNext()) {
while (changeTask.next()) {
changeTask.description = current.implementation_plan;
changeTask.update();
}
return 'yes';
} else {
return 'no';
}
}
