Email notifications not stopping

Hello, 

So i have email notifications set up to the selected individuals when there's an update. 

Cronjob runs every 5 mins so that users get notified as soon as possible. 

This has been working perfectly for the past couple of years until this sunday. Now for some reason it sends a notification every 5 minutes to the selected individuals whether or not there's an update. 

Has anyone stumbled upon this issue? How did you fix it? 

Thank you.