Q&A: Why completion shows differently in Task Log and the Activity/People Logs?

If Learnlists or Channels are set to 'dynamic' this would cause there to be a discrepancy between the Task Log and Activity/People Logs because the addition of new materials to a dynamic Learnlist or Channel forces the 'completion' record to be removed - but not the task layer over the top of this (which remains recognised as completed).
If a task is created for a Team, Group, or Company and is set up to go out to new joiners on a dynamic basis, then for all of the tasks to be included in the Task Log and CSV export, you will need to filter the deadlines back to when the Team/Group/Company task was first assigned (to 'current members').
The Task Log doesn't recognise deadlines for the 'new members' tasks, it only recognises the original deadline of the Team/Group/Company task.