Fibaro detectors send different messages for test and real alarm, and don’t trigger flows in Homey when testing. Maybe this is the same for Heiman? If so then it’s probably near impossible to test it though. With the Fibaro’s I need to rely on the z-wave range check function in the device.
Can you see if there’s regular contact between the device and Homey?
It would be nice if the alarm trigger was always called with a tag to show if it was a test or a real alarm.