Trigger Aeotec Siren Gen5 with burglar alarm

[codepitbull]

I have the Aeotec Siren Gen5 and FIBARO FIBEFGFS-101-ZW5 water sensor with burglar alarm.
I use the most current Z-Wave.me running on a Raspberry with a Razberry (firmware 3.0.4).

Integrating the devices worked like a charm.
Water and burgler alarm from Fibaro work and I see them in the UI.
The siren also appeared and I can manually trigger it.

What doesn't work is getting the devices to connected.
I simplay want the siren to go off when the burglar alarm triggers.

Added the Fibaro-Burglar-Alert in Security->Alarm Condition.
Selected the Siren in Security->Alarm Action->Alarm.

There I am unable to toggle the switch shown in the screenshot:

I still tried saving and activating this configuration, which the UI allows.
Lifting the Fibaro triggers the event but the alarm isn't triggered.

What am I missing here?