Can anyone get to the "PSTN usage details" report in the "Skype for Business admin center"? It was working last week, but today it pulls up nothing and returns "Trouble getting data for this report. If the issue persists, please contact Microsoft support." The Help button at the top-right open a blank window.
There is some on going issues with the SFBO Reporting. The reports are not getting updated in the timely manner. Can you please check with your office 365 portal and see if you have any Health Advisory issued on the Tenant.