Google has changed their API recently so creating Google Analytics charts is temporarily not possible on Explainum and existing charts are not updated.
We're working over a new connector to Google Analytics. We expect that all missing data for existing charts will be loaded automatically when the new connector is ready.
As a workaround for new charts, you can build updatable charts using data from local CSV files put into Dropbox. However in this case you will need to manually update numbers in the CSV files on regular basis. As an upside -- you can combine in one chart visitor stats and any other KPI like revenue, number of orders or anything else (don't forget you can use right Y-axis). Read more details about CSV over HTTP data source.