This happens if the iPad does not sync up the results until after it is due. This may be because the employees turned the iPad off or put it to sleep before it had a chance to update.
Another possibility is that it was taken out of the WiFi range and no longer had a good enough connection to sync up the data. So even though the employees checked and submitted items before the time it was due, our system did not know about it because they had not synced the information. Therefore, the system viewed the list as late and sent out the overdue report.
On your end, make sure you always have the best internet connection possible and employees know to have the iPad connected to WiFi at all times.