Been looking more into this.
Not sure if its because I have two task widgets displayed or not.
But selection in widget of Due Tasks, Due and Overdue task, today and tomorrow only seem to appear in the widget if they have a priority.
If there is no priority they dont show.
Due, overdue and future, I have no idea. For one task list all the tasks show for the other where I have one task with no priority, it doesn't show.
Selecting All Tasks shows all tasks without problem.