An Action/Alert notification is not working

Please see attached files. I created an alert on 7/22 and every owner on my spreadsheet was notified. I have since update the date and the alert on 8/22 but no notifications when out to the owners. I was attempting to use this function to send out weekly reminders to the owners to update the status on each item assigned to them. Can you help me understand why this worked the first time and has not worked since.