I have a manually scheduled summary task that has empty Start/Finish dates and therefore an empty duration. I want to create manual sub-tasks below this summary task, again with no dates or duration. As soon as I create a sub-task, Project changes my summary task to auto scheduled and inserts a duration of 1 day using the project start date for Start/Finish.
How can I stop it from converting my summary task from manually scheduled to auto scheduled and inserting Start/Finish dates?
Context: I am importing data from elsewhere into Project and certain summary tasks may not have Start/End dates defined just yet. I would therefore like to keep the dates empty, explicitly showing the user which summary tasks still require decisions for dates.