Scrolling to lead paragraph doesn't work on pages with no headings.
Compare these two pages, where the first has no headings, and the second has a "Sources" heading near the end:
- https://en.m.wikipedia.org/wiki/List_of_Top_25_singles_for_1980_in_Australia
- https://en.m.wikipedia.org/wiki/List_of_Top_25_singles_for_1981_in_Australia
After tapping the edit pencil, you see the lead paragraph in the first, but you see the infobox in the second: