Reproducing this ticket is tricky because it only occurs some times. The problem happens when the site template is exported to update an existing site. That export does not include the content because it is not needed for an update. If later a new site is created, the export of the last time is fixed.

Here is one way to reproduce it:

1) Create a site template (or reuse an existing one) and create a web content inside. Add an Asset Publisher in a page to show that content for easier testing.
2) Create a site called "Site A" from the site template with propagation of changes enabled. Check that it has been created with the content copied over.
3) Go to the site template and move a portlet to a different column (the goal here is to make any change that fires a propagation of changes).
4) Create a new site called "Site B"

Result: "Site B" does not have the content.
Expected result: "Site B" should have the content copied over.