Is the threshold actually crossed? Check the device's live value.
Cooldown — after a fire, the rule waits cooldownMinutes before firing again for the same device (another device tripping the rule fires straight away).
Monthly action quota — if you've hit max_action_fires_per_month, actions stop until next month. Check Quota & limits.
Allowed actions — webhook/MQTT actions require a plan that permits them.
Endpoint — we sign requests with X-Synacl-Signature: sha256=…; verify your endpoint returns 2xx. Repeated failures appear as action/failed events.