What about changes in any of the Health or Workload badges?
Getting alert on anomalies doesn't really mean something is wrong, it means just that something behaves differently than before
As to drill-down, you can try the "Events" page or the "AllMetrics" page.
On the Events page, you can see events for the self, children or peer objects - use the "E" button to enable those;
then "target, up/down/left-right" buttons to filter. This might help you see what happened.
Make sure to select a suitable time window for the data - e.g. few hours/ before the anomalies started going up and see.
All metrics is also very useful screen, but you need some starting point otherwise it will take some time looking at different graphs