Drilldown for Row not using the field in search if the value for the field is null

[psmp]

I have a Dashboard which returns a table. the Drilldown is selected as Row for this table.

There are 2 rows with DisplayVersion as 2.8.110 and NULL.

When I click on the row with the DisplayVersion as 2.8.11.0, it opens a new window with base query that includes "search "DisplayVersion='2.8.11.0' " and return 223 rows.

But When I click the row with DisplayVersion as NULL, it opens a new window with only the base query and still returns 223 rows.

Ideally it should open the base query + "Search DisplayVersion = "" " and just display one row.

But it is not happening so. Can someone please clarify why?

Image attached for your reference.

[niketn]

@psmp what is the <drilldown> code that you currently have?
Also would it be possible for you to add one sample data each for version null and version not null?

Which is the query that works fine identifying 1 null version event?