Repeat Interval set to 52w but notification is resending every 120 hours

My alert has been firing since Jan 10 and the notification policy is set with a Repeat Interval of 52w. However, I am receiving a notification for this alert approximately every 120 hours. Here are the last two timestamps from the notifications.


Here is where I set the Repeat Interval:

I am unable to find an explanation for this behavior. Any help would be appreciated!!

Your Grafana config is correct. Unfortunately, there is Prometheus alert manager bug:

Thank you so much!