Moving child items when nesting projects

I may be misusing TaskPaper, but when I reorganize projects using the sidebar, the child tasks are left behind. My assumption was that child items are “attached” or “owned” by the parent, and so it’s confusing to me how I might move an entire project into another project without resorting to the keyboard (i.e. cut and paste).

Am I missing something?

Projects do take their children with them, but one source of confusion can be tasks which may intuitively look as if they are children of a project but are actually just following siblings.

Child tasks are those which are actually indented under a project. (Taskpaper is a tab-indentation outliner)

Project A:
- Sibling but not child
- Also not child

Project B:
    - Child 1
    - Child 2
- Sibling but not child 

(Project A here has no children, Project B has two)