You might have clicked/ submitted or closed the notification. By default we set a cookie length of 4 hours for all our widgets. In case a user clicks on a notification/ submits a form or closes the notification, it is not shown again for 4 hours. You can change the cookie length as per your preferences while creating or editing a notification. Here is how you can do it:
Edit/ Create notification>>Go to Visuals Screen>>Advanced Options>>Other Options>>On user action, don’t show again for—-min.>>Save.