BPM task reminders frequency change not reflected for existing notifications?

Summary:

Are BPM task reminders frequency change not reflected for existing notifications? Does the change only show for new notifications?

Content (please ensure you mask any confidential information):

We set task reminder notifications in BPM and for testing purposes, the frequency was set to every 5 minutes after assignment. After the testing was successful, I changed the frequency to every 2 days (this is the client requirement). However, I noticed that for existing notifications, the reminders keep on coming every 5 minutes instead of every 2 days. For new notifications, it looks like the change is reflected. Did anyone also experience this issue? If so, is there a fix?