Monolithic Stair disappears below level

[rdaniel]

Anyone have any trouble with a stair disappearing when the top and base are moved below a level? The attached stair works fine (sans the little notch) until the top and base heights are changed to a negative (Desired base is -3'-0 1/2" below Level 1 and top is -1/2" below Level 1). As you can see the stair works fine, but try to change the heights and see if it doesn't disappear. Any thoughts? I've tried creating it with risers and boundaries, as a run, etc. Just can't seem to get it.

[rdaniel]

Well, I changed the winder from smooth to stepped and that seemed to get it. The geometry of the stair may have been clipping the underside of the stair.

[CAtDiva]

Well, I changed the winder from smooth to stepped and that seemed to get it. The geometry of the stair may have been clipping the underside of the stair.

Thank you so much for posting your solution! Saved me from having to figure out how to explain/express my question.