Hello There,
Thanks for writing in!
Are you using the latest version of the theme? You might need to update to Pro theme 1.2.3 or X 5.2.2 and Cornerstone 2.1.3 which is already available in automatic updates. This latest release contains fixes for several issues so be sure to check out the changelog (http://theme.co/changelog/).
I have investigated this issue in my local install. I am trying to replicate the issue by having a draft post or a schedule post created in Cornerstone. After i save my changes in Cornerstone, the posts is still a draft or a scheduled post. It does not change its status as published.
Are you using a plugin that shares your posts via social networks? I am guessing that the plugin has something to do with it. The plugin wasn’t able to checked whether it is still draft or scheduled post. The plugin might share automatically any post that you created regardless of its status.
Hope this helps.