Slack alerts not alerting

[jcm1123]

I setup the alert service to use Slack and clicking the test button works but I'm not getting any real alerts sent to Slack.
I have the level sent to INFO, which I assume would capture everything.
I also see alerts in the alert tab that should have went to Slack.

I looked in a few different logs but didn't see anything related to Alerts or Slack.

Anything else I can check?

Thanks!