Perhaps your tasks are not yet tab-indented under their Project headings ?
All parent-child relationships (project-task, or task to subTask relationships) in TaskPaper are consistently expressed by tab-indentation.
That can mean that a list of tasks which you intended as children/members of a preceding project, are actually just following peers or siblings of it, rather than belonging to or descending from it.
That might be why, when you click on a project in the sidebar, you get the impression that it is ‘collapsed’. (In fact, for lack of tab-indentation, it just doesn’t have any descendants yet.)
To fix it:
- Go back into a full view (click the filename at the top of the sidebar)
- Select a series of tasks that you want to belong to an immediately preceding project line
- hit tab to make them indented under (i.e. actual members of) that project