Nested Loading Route Problem

I created a jsbin to illustrate the issue: JS Bin - Collaborative JavaScript Debugging

When transitioning to “dashboard/page1” and “dashboard/page2”, the “dashboard/loading” template is correctly rendered.

When transitioning to “dashboard/projects/:id” from any parent page, loading also works.

But when transitioning from “dashboard/projects/1” to “dashboard/projects/2” the parent loading template which is “dashboard/loading” is not being rendered.

I tried to add return true; to the loading action of every Route but it still doesn’t work. The action gets triggered and bubbled but the template doesn’t render.

Am I misunderstanding the bubbling behavior described in the docs?