Hello.
1) user1 create story (text) post in dashboard
2) user1 comment it
3) user2 react to user1's comment
4) user1 delete his story (text) post (comment deleted automatically)
Result: user1 still can see notification "user2 reacted to user1's comment"
Expected result: Notification should be deleted automatically because story post and comment deleted.
Thanks.

I didn't tested it with other post type and content (video, photo, album etc).