Viewtracker doesn't expand

Also posted on AAC - https://answers.atlassian.com/questions/29950412/viewtracker-does-not-expand

We have the viewtracker macro on a page, with expandable option enabled.
When previewing the configuration in the macro editor, the viewtracker is expanded correctly,
but this doesn't work on the page itself. It does count correctly but clicking the arrow to expand
the list doesn't provide the list.
Any idea what is causing this behaviour.