M2Mqtt crashes oculus app

Hey,

i am just want to use the mqtt functionality of the m2mqtt package. I imported the downloaded .dll file into the assets and used this snip of code to connect & send:

Code (CSharp):

1. using System;
2. using UnityEngine;
3. using uPLibrary.Networking.M2Mqtt;
4. using uPLibrary.Networking.M2Mqtt.Messages;
5.  
6. public class SendSomething : MonoBehaviour
7. {
8.     MqttClient client = new MqttClient("192.168.178.22");
9.     string clientId = Guid.NewGuid().ToString();
10.     // Start is called before the first frame update
11.     void Start()
12.     {
13.         string clientId = Guid.NewGuid().ToString();
14.         client.Connect(clientId);
15.         //client.MqttMsgPublishReceived += ClientOnMqttMsgPublishReceived;
16.  
17.         // Subscribe to topic
18.         //client.Subscribe(new[] { "/testing" }, new[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });
19.     }
20.  
21.     private static void ClientOnMqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e)
22.     {
23.         var message = System.Text.Encoding.Default.GetString(e.Message);
24.         Console.WriteLine("Message received: " + message);
25.     }
26.  
27.     // Update is called once per frame
28.     void Update()
29.     {
30.         //var enc = new System.Text.ASCIIEncoding();
31.         //var message = enc.GetBytes("message");
32.  
33.         //client.Publish("time",message);
34.     }
35. }
36.  

In Unity the code and the MQTT-Function works well. But after deploying on the oculus quest device the homescreen with the "Made with Unity"-Sign is shown for a few seconds. After that, the Sign disappeares and the screen is freezing.
It must me something at the "connect", because when i am commenting out the "connect" everything is working normally.

Can anybody help me?

Thanks for all,
Matthias