How to undo 'Don't Suggest Calendar' for Siri Suggestions on iPhone?

How to undo "Don't Suggest Calendar" on Siri Suggestions widget?

I recently accidentally selected "Don't Suggest Calendar" (or Suggest App Less) on the Calendar app from the Siri Suggestions widget on my iPhone.Here is what I have tried so far to get it back:

1. Checked Settings > Siri & Search > Calendar to make sure Learn from this App, Show App on Home Screen, and Suggest App are all toggled ON.
2. Restarted the iPhone.
3. Frequently opened and used the Calendar app manually for several days.

However, Calendar is still excluded from the 8-icon Siri Suggestions grid.

How can I clear or reset the "Don't Suggest" history for a specific app so the Siri algorithm starts recommending Calendar again?

Thanks for your help!