We have shipped a large number of improvements that have largely decreased the number of posts failing to appear in Publications. In addition, work has been done to stabilize other surfaces relating to Publications and their layouts.
We are confident that a large majority of the behaviors observed have been stabilized, but acknowledge that some users may still experience abnormalities.
If you experience undesired behavior in your publication, please contact us at help.medium.com so that we can better understand the nature of the problem, and address it as soon as possible.