Thanks for the answer. I don’t even know about the “move old data to archive” functionality.
I looked to the preferences hoping I found why my previous 3 completed tasks where deleted but found nothing. I really wonder what happened to those tasks.
I thought I could use OF completed perspective to create a log of what I have accomplished but I can’t go this way if my tasks disappear without me understanding why!
I revised my projects this weekend. I wonder if this could explain why my completed tasks have gone away.