What happens when I choose whether to sync the official roll call period for the day, or all rolls?
When it is enabled, you can select to have only the official attendance roll as the official roll for the day. This determines which rolls will be automatically sync when submitted or modified. Syncing all rolls will use every submitted roll to automatically build up an overall view of the students daily attendance based on their attendance throughout the day.
Syncing just the official attendance roll will make Attendance reflect the attendance data of that roll which will then have to be modified within Attendance to reflect their actual attendance.
It is important to Read the details on screen under Automatic Sync to Overall Attendance.