I knew that workflows were deleted every ~60 days, but I didn't know tasks were ever automatically deleted. My customers rely heavily on this information being available at all times. Is it possible to allow the workflow items to be deleted while preventing the tasks from being deleted? There isn't a visible retention policy on the tasks list that we can turn off or anything like that which I can see in the UI.
edit: After doing more research on this, it looks like tasks that have been completed more than 60 days ago are deleted. I tried updating the modified dates to make them appear as if they were only completed recently, but it seems it doesn't use that date in this determination.
However, I have noticed that if I create a NEW task on the Task list itself without a workflow or if I make a copy of a task created by a workflow, the task is created without a WorkflowInstanceID value (it is null instead of a guid). Can anyone please confirm that an item without a workflow instance ID will not be deleted? I can't change the timing of 60 days, and I can't wait 60 days to know if this solution will work.