Understanding slack alerts in grafana

i am a little bit lost and trying to understand how alerting works in grafana when redirected to a slack channel…

So i a have created a slack alerting rule and i would like to evaluate it every 5m for 15m and send an alert … the condition i have satisfies for the alert to be sent… however i dont receive alerts every 15m… when i see the alert dashboard it does say it has been firing for 1hr… but i never see the alert… even when i test the rule it says its alerting. i did a test connection to slack and it works fine as well…

Any help is appreciated…

thank you!