Anki Manual next page button is broken on some pages

Next page button on Install & Upgrade - Anki Manual leads to current page. Seems to be that way for first page of 3 levels deep hierarchy.


The problem seems to be that the same file is used for a chapter and its first subchapter, presumably to avoid a redundant landing page and move to the first subchapter immediately. Unfortunately, mdbook can’t cope with this apparently.
A workaround would be to make it a draft chapter, but then it wouldn’t be clickable in the sidebar.