I noticed that in the sample document the numbering scheme uses a List Number style (Multilevel List, Define New List Style) as opposed to a MultiLevel List (Multilevel List, Define New MultiLevel List).

In my testing, the problem you're experiencing does not occur with a Multi-Level List ("MLL").

Based on the name of your styles, I'm guessing you are in legal; so am I. In the case of your sample document the "package" is called "M&ANumbering."

Stefan's workaround was also successful for me. However, I have another solution that you might find useful:

1. Open your sample document.
2. Go to the Developer tab, click Document Template, Organizer.
3. On the left, scroll to "M&A Numbering", click Delete; click "Yes"; click Close
4. Select your list, press Ctrl+Q
5. Right-Click on number 4; set number value to 9

Basically, what we've done here is convert the list number style to a MLL.
Is this how you expected the list to work?