Test a copy of the website on another environment without firewalls/rewrites, if you can configure it ok there, it means that there is a problem during the communication with google api servers or during the getting of the required information from google services.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items