Would like to get some help with DataDog failing to send alerts for all errors within a specified evaluation window.

Given the above DataDog Logs Monitor Edit screen, have specified a 5mins evaluation window for alerts to be sent. However, an alert is sent only for the first alert sent within the 5 minute window. Any additional errors triggered within the same window are not sending additional alerts.
Do you guys know if it's default DataDog behaviour or this can be changed somewhere.
Thanks