Examine your STL (or the source file that’s used to product the STL). You may have a thin wall there. If it’s thickness is less than the layer height, the slicer will skip it. When you scale it up, everything gets bigger including that thin previously-invisible layer and now it’s visible.
You could also turn on variable layer height for the smaller version and if you do, I bet that top layer shows up there, too…
Or rotate your sliced sections 90º so that the top surface is vertical instead of horizontal and it might show up that way, too, depending on your settings for wall generation.