Anomaly detected activity alert is just a post to make one aware that there is an Anomaly. Meaning the Anomaly detected activity alert is just to give information that something happened, but it's doesn't give an in detail information and that's all it's supposed to do, because it's a big picture of an Anomaly detected activity. If more information about the Anomaly detected activity is required, then it can be found under Critical Activity section on On-Demand Audit page. To view the details of the events that triggered the Critical Activity:
Go to Critical Activities tab in Audit
Select the Critical Activity "Unusual increase in Shared OneDrive and SharePoint files"
Click the triangle that appears on the timeline for 08/07/2024 at 8:00 PM
A search grid with the events that generated the anomaly will be displayed