The following message is displayed in ATP, "No advanced analytics events occurred in the last 3 days. See why advanced analytics events are not appearing in EDR help for more information".
Release : EDR 4.4.0
Component : TAA
Within the External Communications Policy of the SEPM, enable "Send pseudonymous data to Symantec to receive enhanced threat protection intelligence"
This behavior is documented in the What's New section of the EDR 4.4 Release Notes as "Receive System Health notifications when Symantec EDR has no event detections for three days"
Release Notes are available here: