Motion Sensor association issue

I just install à new motion sensor in my Veraplus. It’s an AEOTEC Trisesensor. The pairing was quite easy and motion, temp ad lux are displayed in the vera interface.
My issue: every time the motion sensor detects automatically my siren starts !
It seems that there is a direct association between both devices.
I never build this association and I don’ t understand how the sensor identified my siren and decided to couple it.
Now I want to delete this association. But as I never play with association function I am a little bit lost. I read that I should delete a group…But how to do ? When I go to association I found only to create a new group but no to delete one.
Please some help .

It’s not a Z-Wave association.

Instead look in the Dashboard - My Preset Modes

And turn off the Siren button under What to do if an armed sensor trips.