I'm a bit unclear on your setup but from what I can tell you might have a problem with the Time Constraint. It is set to 360 minutes = 6 hours and this means that all the triggering tasks must finish within 6 hours from each other. In your case the first task ends at 3:35, e.g. 6 hours and 25 minutes before the fourth task is even triggered and so the final task won't activate.
More generally the reliability of task chains have improved in later version of Sense and especially if you have large number of triggering tasks it might make sense to try and upgrade.