A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
There's a workaround that I found that might be helpful to others that is having this issue.
What you can do on your pc is that you can create a new list with a "new box" on the same page, put in the new list and discard the old list completely.
This way, the old list will be deleted forever, so you don't have to keep the long completed list that you already cross out on the phone. In addition, the phone will always combine your new list in the new box as if it's one list.
Hope this method helps, as you can always do everything on your desktop without using the phone.
Nick