Go to http://en.m.wikipedia.beta.wmflabs.org/wiki/0.28647961229659646#/notifications and click the close button.
Expected behavior: The overlay closes and you see the article.
Actual behavior: Your browser goes back to the previous page that was loaded before.
Version: unspecified
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=65041
https://bugzilla.wikimedia.org/show_bug.cgi?id=67639