Hello.
1. User1 posted comment.
2. User2 replayed to User1’s comment
3. User1 get notification (about reply)
4. User1 replayed to User1’s comment (to continue talking with User2)
Result: User2 didn’t get any notification, discussion is stopped.

Expected result: all users who replayed to comment (posted sub-comment) should get notifications about new sub-comments from any users.

Thanks.