Hi there,
Thanks for writing in! Upon checking your site, I see the following errors on web console error log.
MissingKeyMapError
NoApiKeys
There were some changes introduced to Google Map API by Google, so that is why it will require an API key.
Google Map API key field is now available in Cornerstone (see: http://theme.co/changelog/#cornerstone-1-3-0).
Please watch the below video for more information.
Hope that helps.