PivotTable Options: show items with no data greyed out

[JFCLUK]

I have a pivot that is driven by a slicer. When I select items from the slicer, rows in my table with no data disappear. I have tried to select: PivotTable Options>Display>Show items with no data on rows - however, this is greyed out. In Field Settings>Layout&Print>Show items with no data IS SELECTED.

I want to retain the structure of my pivot table and if the slicer selected presents no data in 9 out of the 10 rows, I still want to show the 10 rows (and not the only 1 row with data).

Please can anyone help - I've spent about 4 hours trying to resolve this! Once I can fix this, I can share my dashboard with my boss!

 

[JFCLUK]

I also want to (blank) to stop reselecting itself when the table refreshes!