In recent articles that have been published, images that are selected to be centered no longer appear to be centering. In the editor, they will center properly, but after being published, they will auto-align to the left side of the article. You can see this in some of pictures in this article.

@churchyard was trying to center images in his upcoming article but also had the same problem. He created this test article that demonstrates the problem. He also sent a diff for the CSS to fix the problem.

Have any idea what's happening, @ryanlerch?

--- style.css   2016-07-14 11:08:26.718861950 +0200
+++ style-new.css       2016-07-14 11:10:10.446361149 +0200
@@ -1163,6 +1163,10 @@
        border: 1px solid #EEE;
 }

+.aligncenter img {
+       margin-left: auto;
+       margin-right: auto;
+}

 .post-content .alignleft,
 .post-content .alignright {