With the STHM setup and in an Armed mode, unplug the network connection from the Hub and trigger one of the sensors that’s configured in the STHM. Does any siren or light configured in the response section of the STHM come on? None of mine every did without an internet connection.
So I created a few different intrusion response Automations as an alternative to the STHM since Automations can run local on the Hub without the internet. One intrusion response Automaton runs local to turn on local Zigbee and Zwave devices like sirens and lights, and another Automation runs in the Cloud which is for notifications that maintains the text message alert entries unlike the STHM which kept losing them. As for Armed Away, Armed Stay, and Disarmed modes, I’m using an Edge Virtual Text device by @Mariano_Colmenarejo which also runs local on the Hub without the internet.