Stair disappears in drawing, shows fine in view accessed from drawing

[Ignacio Azpiazu]

This stair (the exterior one; bottom one in the pictures) shows fine in 3D. It is placed on the story below, set to show one story up. After months in the project it disappeared from the (plan) drawing, but when I open the view from the drawing it is right there. In desperation I exploded a copy, which exploded to nothing. This has happened to me before, weeks or months ago; back then I redid the stair by duplicating a similar one from somewhere else in the file. Pen sets are fine. I traced it with lines, on the same layer, and those lines show in the drawing. AC 24 USA latest build. [Edit: it also disappears on the section.elevation windows. On the 3D window, with convert to morphs it vanishes.]

[DGSketcher]

Has someone possibly changed the renovation status or layer of the stair object or modified view settings or a layer combo? If it present in the model and you can see it when opening the source view from the layout suggests a display setting has altered. When you open the source view and click in the workspace does the view map highlight the expected view in the list?