show comment in pull request activity

0, user A create a pull request
1, user B put inline comment => these comments show in the pull request activity, and A received notification email => OK
2, user B push a commit to the branch based on B's feedback
3, user B start code review again, put inline comment on the new commit => these new comments will not appear in the pull request activity => X, suppose to appear in pull request activity as step 1