Do you have the WP Discourse Publish as Unlisted Topics option enabled? The difference between the posts_count and the filtered_posts_count in the discourse_comments_raw metadata suggests that there are two small action posts in the topic. There is an issue with the WP Discourse webhook refresh function when there is a discrepancy between the posts_count and the filtered_posts_count. This is something I will deal with, but I don’t think it’s related to the issue you have with a post that is not receiving comments.
For the issue with the post that is not receiving comments, do you mean that the link to its Discourse topic is not being displayed, or is the issue that the link is displaying “start the discussion” instead of “join the discussion”?