There are many instances of where Office 365 ceases to generate and provide reporting data in a reliable manner. See Alan Byrne's piece on the topic at https://www.petri.com/office-365-meets-sla-fails-elsewhere It's a sad state of affairs that has existed for many months now. Microsoft needs to get a handle on this area.
Thanks again for flagging. I'd like provide an update on the status of the issue:
We've identified and fixed a code issue that was preventing updated usage report data from being processed in a timely manner. We're now processing the backlog of report data, and expect usage reports to be completely up to date by the end of this week.
We have posted this on the Service Health Dashboard under MO91648.
Please refer to the SHD for more details and further updates.