Why is the Header of the Theme Not Styled/Functioning Like the Demo?

All of our themes (except for Rubric) use a Site Header module for the header. If you are instead seeing a Menu module in the Website Header global then you have run into a strange bug of HubSpot's. Sometimes after downloading a theme the HubSpot system will replace the contents in the global header with its own default modules.

In most cases you should be able to resolve this by opening the Website Header global, going to View > Version History, and restoring it to the first version.