With initial values of above style properties, reducing window width will eventually show left side cut-off/clipping problem even though some horizontal scrolling is possible (but not to the cut-off/clipped areas). If image is hidden then the span with white-space:pre will create the issue but at a smaller window width.
Setting container flex: justifyContent to "initial" will solve the issue by introducing wide enough horizontal scrollbar!
Setting item div: overflowX to "scroll" introduces a scrollbar at bottom of item div which is sometimes off the screen, and so is not helpful.