Conflict when adding a Z2M device

Configuration
3

Here is the JSON associated with the device when I press « Add to Gladys »:

{
  "name": "Bureau Capteur_presence",
  "model": "RTCGQ11LM",
  "external_id": "zigbee2mqtt:Bureau Capteur_presence",
  "features": [
    {
      "name": "Battery",
      "read_only": true,
      "has_feedback": false,
      "min": 0,
      "max": 100,
      "category": "battery",
      "type": "integer",
      "unit": "percent",
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:battery:integer:battery",
      "selector": "zigbee2mqtt-bureau-capteur-presence-battery-integer-battery"
    },
    {
      "name": "Motion Detection Yes/No",
      "read_only": true,
      "has_feedback": false,
      "category": "motion-sensor",
      "type": "binary",
      "min": 0,
      "max": 1,
      "unit": null,
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:motion-sensor:binary:occupancy",
      "selector": "zigbee2mqtt-bureau-capteur-presence-motion-sensor-binary-occupancy"
    },
    {
      "name": "Temperature",
      "read_only": true,
      "has_feedback": false,
      "min": -100,
      "max": 150,
      "category": "temperature-sensor",
      "type": "decimal",
      "unit": "celsius",
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:temperature-sensor:decimal:temperature",
      "selector": "zigbee2mqtt-bureau-capteur-presence-temperature-sensor-decimal-temperature"
    },
    {
      "name": "Average Voltage",
      "read_only": true,
      "has_feedback": false,
      "min": 0,
      "max": 10000,
      "category": "switch",
      "type": "voltage",
      "unit": "millivolt",
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:switch:voltage:voltage",
      "selector": "zigbee2mqtt-bureau-capteur-presence-switch-voltage-voltage"
    },
    {
      "name": "Decimal Brightness",
      "read_only": true,
      "has_feedback": false,
      "min": 0,
      "max": 100000,
      "category": "light-sensor",
      "type": "decimal",
      "unit": "lux",
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:light-sensor:decimal:illuminance",
      "selector": "zigbee2mqtt-bureau-capteur-presence-light-sensor-decimal-illuminance"
    },
    {
      "name": "Decimal Brightness",
      "read_only": true,
      "has_feedback": false,
      "min": 0,
      "max": 100000,
      "category": "light-sensor",
      "type": "decimal",
      "unit": null,
      "external_id": "zigbee2mqtt:Bureau Capteur_presence:light-sensor:decimal:illuminance",
      "selector": "zigbee2mqtt-bureau-capteur-presence-light-sensor-decimal-illuminance"
    }
  ],
  "should_poll": false,
  "service_id": "515a15a0-d9e5-4d2b-89bf-80aca56106f7",
  "room_id": "c571780a-4da5-4801-8731-8735a8e2c5a2"
}

Is it because the same feature is present in duplicate, or because the unit is null for one of them?