Filter on Task Status field is not filtering out Tasks

When applying the filter Task Status != Completed, the list still shows Tasks that are Completed.

Task Status is a field attached to a User Story that is based on the rollup of all the Tasks associated to the User Story. The field’s value will not be set to Completed unless all the Tasks in a User Story are in the Completed state.

In the example above, the value for the Task Status field remains In-Progress because there is still one Task In-Progress.

When viewing a list, such as shown above, the filtered fields set are dependent upon the work item type being displayed in the list. In the above example, only fields on the User Story work item (HierarchicalRequirement in the Web Services API doc) are available to filter.

The Task Status field is a calculated field on the User Story work item that will always be:

• “Defined” only if all Tasks are Defined
• “Completed” only if all Tasks are Completed
• “In-Progress” if one or more Task is In-Progress