[Observium] Can't get alert to trigger

We are just now setting up our alerts for the first time and cannot get even our most basic one to alert successfully.

We added an alert checker applied to all devices and all entities. The condition is storage_perc gt 80. We then regenerated our alerts and the alert was assigned successfully to all of our devices. On the alert page that shows a summary of the alert and the devices that it belongs to, I see all of our devices listed and all of them have a status of OK even though one of them is currently sitting at 87% utilization. If I mouse over the "state" column for that entity, it confirms that it is at 87 right now.

What are we doing wrong? Why isn't this alert triggering?