You are using the Delete Old Pending Alert flag in your Alert rule but it does not delete old Pending Alerts if the new Alerts are triggered by a new record with same effective date.
Employee Central - Alerts & Notifications
Reproducing the Issue
Example: Alerts are triggering off Contract End Date in Job Information
1. On June 1st a record was added to Job Information with a Contract End Date which satisfied alert rule.
2. EC Alerts & Notifications Job runs.
3. Alert is queued.
4. Then a second record is added on June 1st with a new Contract End Date. This also satisfies the rule.
5. EC Alerts & Notifications Job runs.
6. The Alerts for new record are created but the old Pending Alerts are not removed.
This is an expected limitation of the new Delete Old Pending Alert Flag.
This occurs because the system keeps the Alert for a record based on the latest effective start date - and both the Alerts in a scenario like this link to records with same effective start date.
For more information please see the How Old Pending Alerts Are Handled section of the Handbook.
Delete, Old, Pending, Alert, function, flag, alerts, rule, manage, tool, notifications, EC, same, date, effective, time, record, slice, multiple, new, start, date, INC0784650 , KBA , LOD-SF-EC-ALR , Alerts & Notifications (saveAlert - EC Core only) , LOD-SF-EC , Employee Central , Problem