A user creates a new task called "Morgen" with a start and end date of the next day.
Additional he creates two subtasks called "u1" and "u2"without start and end date.

If the user clicks on the print button, the task and subtasks will be displayed correct.

User changes the view to the filter "Morgen". Task and subtasks will be still displayed correct.

But if the user clicks on the print button, both subtasks will be gone.

The printout should match with the current view.

There is already an open issue about non working filters. Could be related.
https://issues.kolab.org/show_bug.cgi?id=5470