Similarly to the recently fixed changed-follow-status-redirect bug, for manga with chapter lists that span 2+ pages, the pagination links use the old url scheme:
mangadex.org/manga/###/.../chapters/2
instead of the new:
mangadex.org/title/###/.../chapters/2
Edit: It's been fixed
mangadex.org/manga/###/.../chapters/2
instead of the new:
mangadex.org/title/###/.../chapters/2
Edit: It's been fixed