My overall desire for this would be as follows;
1.Check the host every 2 minutes.
2. If the host goes offline, send a notification
3. Check again in 5 minutes, if it is still offline send another notification (do this 2 more times)
4. If the host recovers, send a notification.
It retries in an interval of 5min for 3 attempts
UP->Down (soft) [1st attempt]
Down (soft) → Down (soft) [2nd attempt]
Down (soft) → Down hard [3rd attempt]
with the change to the hard state notifications get triggered.
Your notification template is missing the “transition type” Problem
The notification apply rule you have configured does:
delay the first notification after a check reaches the hard state for 120s
after this send a notification every 15min (900s) if the check is still in an hard problem state
So if you want to have a notification to be sent every 5 minutes if the host is still down you need to set the notification interval to 5m (or 300s). If you want it to happen immediately clear the notification delay. If you want the additional notification to stop after some time you add 20m (e.g.) to the “last notification” field, so that you don’t get any notifications after 20 minutes of the host being down.