Duration getting updated to inaccurate number when the tasks are assigned to an iteration

[BalajiCh1]

Hi All, 

I have a project created with a set of tasks. I had updated duration, planned hours and assigned the tasks to an agile team. Once the tasks were assigned to the agile team, those tasks were showing up in the team's backlog. When I added few tasks from the backlog to one of the iterations, the duration of the tasks in the tasks list in the Project page got updated to very large numbers (57 days) whereas the original duration i had updated is very less ( 1 Day). Not sure why this is happening. How to retain the original duration of the task after it is getting assigned to an iteration.

Please provide your inputs. Thanks in advance.

[KellieGardner]

what is the duration type of the tasks in the project? If it's calculated, then that could be your culprit.

Calculated Work Duration Type 

Work Required (Planned Hours) = (Duration of the task in hours) x (The number of resources assigned to the task)

Overview of Task Duration and Duration Type | Adobe Workfront