How do Lenses alerts to Slack work?

I set up a Slack channel on Lenses to send alerts when there are more than one message with a few minutes between them, but they don’t appear in more than one.

The default behavior is to display a notification and not send another one within the chosen time period if another notification has occurred within that period. This behavior is to prevent information overload. Only when an alert is dismissed can it be triggered again and a new message sent.