Hi all,
I originally reported this to Support as a bug but was told that a) the engineers are aware of the issue and b) they don't plan on fixing it/considering it part of the feature.
When creating a Pivot Table dashboard widget, you select 2 fields to break and group by - thus creating the pivot table! When setting the location, if an item exists there but is missing 1 of 2 fields, the line item will show as N/A. All other cells in the pivot table can be clicked on and doing so will bring up the filtered work in a popup. Clicking on the N/A cell does not bring up a popup, thus making it difficult to locate these issues.

Ideally, clicking on any cell in a Pivot Table should bring up the affected items, regardless if they are N/A or not. Consistency is key for an optimal user experience! 😉