Agile Phases for Projects do not have the proper related lists.
This was happening simply due to not having the "link" and "phase_type" fields on the pm_project_task form.
The proper related lists are shown/hidden based on the phase_type selected. Currently, the two Client Scripts that control this are the following:
"Hide the Project Task Related List"
"Hide test cases related list"
These both use g_form to take in the phase_type value but without it being present on the form itself, it simply will not work.
Once this is fixed, you will see the proper Related Lists of "Stories" and "Time Cards". Note that some should be hidden such as the one for Test Cases.
Also note, that these fields are hidden by default on the form so they should have no impact after adding them. This is controlled by the "Hide Link, Phase Type and Rollup Fields" UI Policy.
To add the fields, follow the steps below.
1. Navigate to any pm_project_task record that is an Agile Phase
2. Right-click the form header and go to Configure > Form Layout
3. Add the "link" and "phase_type" fields to the Selected box on the right side
4. Click Save