Homeassistant.turn_on turns a switch on and then immediately back off?

I have a series of automations for an alarm system. However, the specific automation which is intended to turn on a siren and then send a notification ends up turning the siren on and then immediately off again.

The automation:

alias: Alarm - Triggered
id: alarm_triggered
trigger:
  - platform: state
    entity_id: alarm_control_panel.alarm
    to: triggered
action:
  - service: homeassistant.turn_on
    entity_id: switch.siren
  - service: ifttt.trigger
    data_template:
      event: alarm_triggered

And the latest trace:

And related logbook entries:

If I dig into the related log entries for each step, it seems to indicate that the siren is turned off during the ifttt step for some reason, which is even more baffling.

Note that this used to work for the longest time but at some point in the last few months (I think; it’s been broken for a while and I haven’t had time to investigate until now) it broke.

Did you try disabling the ifttt trigger action? Check if the siren is switched off or not?

I figured it out. I manually triggered the siren switch and it turned itself back off after a few seconds. Looking at the ZWave logs, it did not receive a response from the device. I re-interviewed the device and everything started working again.