That is what I see on mine. The temperature reflects the “Last Updated” time. If no events are triggered this does not get updated. I tap the “Upadate” button to refresh the temperature. It also updates when you toggle arm/disarm or enable/disable or if you use live view.
I assume this is to conserve battery.
An update/refresh would be nice. If someone uses this to poll they probably need to be warned it could reduce battery life.