Description questions appearing in the quiz reports

Steps to reproduce:

1. As a teacher, create a quiz containing a Description item and a real question.
2. As a student, attempt the quiz.
3. As a teacher, go to the quiz grades report (e.g. https://qa.moodledemo.net/mod/quiz/report.php?id=30&mode=overview)

Expected result: The Description does not appear in the report, does not take up a question number, etc.

Acutall result: The description appear, numbered Q1, so the acutal Q1 appears as Q2.