On April 9, 2021 we updated most of the report templates that are supplied as an example report with the Google Data Studio connectors we provide.
Because of an error in Google Data Studio sometimes the selected date range in the report (by using the date selector) was not enforced correctly in the example report.
As soon as we were aware of this problem we investigated the problem and found that it was caused by Google Data Studio while creating a copy of the master template. We developed a fix (workaround) and updated all the example reports in such a way that the error no longer can occur.
But please be aware that example reports created before April 9, 2021 can show data in charts that does not belong to the selected period in some cases.
All the reports created after April 9 do not have this problem.
And reports created before April 9 can be fixed by clicking the charts (of type Scorecard, Line, Bar and Table) one by one and selecting 'Default group: Report Date' as Date Range Dimension.