While quickly discussing an issue (where native comments from others were posted as from me on micro.blog) Aaron Parecki pointed out on the #indieweb slack that the microformats markup was incomplete in that the comments were missing h-cards.
The h-card gives machine readable information about the author of an on page element so it was wondered if this was the cause of the issue.
Manton has confirmed it's not but that doesn't mean I shouldn't fix things.
So, hopefully, I’ve made some changes to the theme that resolve this and correctly identify the author (name and URL) for each comment, although I did have to force every comment to have the class
h-as-reply to ensure child comments (replies to replies) are distinguished from their parents.
To ensure correct parsing I also had to add a filter to the
comment_text() function so that the comment body was marked up with the
function add_class_comment_text($content) return "<div class='e-content'>" . $content . "</div>"; } add_filter('commenttext', 'add_class_comment_text');