Try to use something other than the 'Built-in text' object.
In your first screenshot, the "Show On" field is set to "Home & One Story Up". Both of these Stories are "Relevant Stories" because the 3D geometry of the Stair goes through these Stories.
In the "Up / Down Text" page, the "Show above Relevant Stories" and "Show below Relevant Stories" options appear only when they are relevant.
For example, if you set your "Show On" field to "All Relevant & One Story Up" option, and your Project has a Story above the Top Relevant Story of the Stair (e.g., the Stair goes from Story 0 to Story 1 and your Project has a Story 2), then the "Show above Relevant Stories" options will appear on the "Up / Down Text" page because they make sense and you can set them.
I hope this explanation makes sense.
Thanks Laszlo... I understand now. Unfortunately that doens't really help solve the problem of having the "down" text only show on the upper level, while the "up" text appears on only appears on the lower level. That got the walking line to work... maybe the text representation will be next?
Can you show a screenshot of exactly what results you wish to achieve on both Stories? Then we will see if there is a solution.