MQTT Discovery Detecting Entities

Ensure it contains unique_id and the value for identifiers is a list.

{
  "name": "AQISensor",
  "device_class": "aqi",
  "state_topic": "device/aqi/500291D66C79",
  "unique_id": "put_something_unique_here",
  "device": {
    "identifiers": ["aqi"],
    "manufacturer": "SuperJonotron",
    "model": "PMS5003",
    "name": "PMS5003"
  }
}

For more information, refer to the example posted here: