Inconsistent "[" "]" moving between files in review to unread comments

When moving between unread comments held in different files within a review - the first time "]" is pressed the user is navigated correctly to the next unread file. However after returning to the previous unread comment and then pressing "]" again to navigate to the next unread comment the user is taken to a point within the code in the file where the desired comment is held but not the desired comment.

Please see attached video for clarification.

This has been tested and reproduced in Chrome, Safari, Firefox & IE