I have the latest install of perch (3.1.5) and blog (5.6.1).
Making a change to a blog's meta/social data causes the post's category to be lost (even though admin thinks it's still there). I have to go back in to the main part of the post and resave to get the post's category to be recognised again. It's very difficult to keep track of which posts might be missing from a category or not.
* Make a change to a blog post's meta/social data eg. change the author or allow comments.
* Check that it's category is still ok on the main part of the post - and it is - the category checkbox is still ticked.
* Go to the blog on the site, and click the category to see a list of the posts with that category. That particular post has gone - even though ADMIN still has the category assigned.
* Go back into admin and Re-save the blog post
* The post is now included in the list when you click the category.
I did see a ticket on the old system over a year ago with this issue. Is there any news on a fix for this?