Error in recv: 9 on disconnect() about kmqtt HOT 12 CLOSED

internal interface MyMqttClient {
    suspend fun subscribe(onReceive: (String) -> Unit)
    suspend fun unsubscribe()
}

internal class MyMqttClientImpl {

    private var job: Job? = null
    private var client: MQTTClient? = null

    override suspend fun subscribe(onReceive: (String) -> Unit) {
        client = createMqttClient(onReceive)
        client?.let { client ->
            
            job = scope.launch {
                 try {
                     client.subscribe(listOf(Subscription("my_topic", SubscriptionOptions(Qos.EXACTLY_ONCE))))
                     client.run()
                 } catch (ex: Exception) {
                     // handle exception
                 }
           }
           job!!.start()
        }
    }
    override suspend fun unsubscribe() {
        client?.let { client ->
            client.unsubscribe(listOf("my_topic"))
            client.disconnect(ReasonCode.SUCCESS) // crashes here, doesn't crash without this line
        }

        job?.cancel()
        job = null

        client = null
    }

    private fun createMqttClient(onReceive: (String) -> Unit) {
        return MQTTClient(
            mqttVersion = MQTTVersion.MQTT5,
            address = "my_address",
            port = 1, // my port 
            clientId = "my_client_id",
            userName = "my_username",
            password = "my_password",
            tls = null,
        ) { publish ->
            // handle incoming events
        }
    }
}

override suspend fun unsubscribe() {
      job?.cancel()
      job = null
      client?.let { client ->
          client.unsubscribe(listOf("my_topic"))
          client.disconnect(ReasonCode.SUCCESS) // crashes here, doesn't crash without this line
      }

      client = null
}