A custom drop down field was created for Features and/or other portfolio items at the Project level, visible to current projects and children. The field is available and present on the details screen and is functional. It is listed and selectable as a column on Portfolio Items lists.
They are present and able to be selected from the column picker on the Portfolio Items lists.
They are visible and able to be selected from the Dependencies tab for Portfolio items, however after selecting them in the column picker and clicking 'Apply' they do not create a new column and subsequently are de-selected in the column picker.