Can you post a screenshot of your template, making sure to show the notes field for the template and the start and due date columns?
If you don't spell the placeholder exactly the same in the notes field and where you use it, no substitution will be made, and no warning given.
Did you heed the following line in the instructions?
Note, the project must have a start or due date (or both) or the script will not set dates on the actions.