To address this issue follow these steps;
1. Open the feature from the Portfolio Items page to the QDP editor
2. Click on the 'book' icon in the header of the feature to open the child user stories in a list view on the left side of the screen
3. The list view will show all user story children and the associated projects.
4. Identify and reassign the 'missing' user story to an appropriate, opened project.
5. The feature should now show the correct rollup for count and points.
6. This process may also involve opening the user stories to see any associated defects as well.
The following screen shot illustrates the QDP editor panel and list view from which this issue can be addressed. Note that a full examination of the revision history for the feature may also reveal evidence of the missing or unaccounted for user story.