In order for the New Tasks, Today, Upcoming, and Later sections to be displayed, they must contain at least one task. If you’re not seeing your Later Section it is probably because it’s empty. Simply mark one of your tasks for Later (using the Tab+L shortcut) and it will reappear.
Tasks do not sort themselves within these sections, but you can move them using the drag & drop feature to organize them in your order of preference!
The task was probably moved manually by mistake (only tasks with a due date will be auto-promoted
When assigned to you, tasks automatically and always land in the “New Tasks” Section. From there you can sort them in the Section you want: Today (Tab+Y), Upcoming (Tab+U), Later (Tab+L).
Hope this helps!