I've had this issue for a while yet and only now I've made an effort to correct it. I started noticing that when I published a new article, it would appear at the top of the list of articles, as it should but when I publish a new article, it would randomly place it down the order and older post would appear below the new post. Of course this is not how I wanted my articles to be displayed, rather the correct order should be the most recent article first. I finally found this post that help in correcting this issue.
How to Control Article Order on Joomla
What this meant for me was that once I set the order to "No, Order by Primary Order" and "Default" this half fixed the issue. I then needed to go back into all my articles and make sure the "Start Publishing" date was correct, by clicking on the little calendar and hitting the day that I created the article. That seemed to finally fix my article order problem. Hope this has help anyone with the same Joomla issue.
