Troubleshooting Mixpanel Native Alerts for Event Notifications

Using Mixpanels native alerts seems a bit buggy. I have an alert that is based on an insight report getting any events: I've tried with above 0 and now trying -1 but despite there being content in the report, the alert isn't getting sent. Is there anything I can do to force the alert or make sure that it gets sent when the insight report gets > 0 events?