Device trigger and retain flag

[ChristopheHD]

Hello,
I'm trying to implement a water sensor and decided to implement a device trigger like for buttons. Here is my mapping:

device_config: command: "" channel: "" log_learn: "" direction: "" answer: "" entities: - component: "device_automation" name: "trig_water" config: automation_type: "trigger" type: "water_detected" subtype: "sensor" topic: "" retain: false payload: "17" value_template: "{{ value_json.WAS }}"

The event is correctly triggered but because of the retain flag in MQTT, the event is again triggered at each restart of HA. Anyone know why all enOcean MQTT packet are flagged retain ? Any idea on how to handle this issue ?

Thanks