Laravel and Pusher - API message not sent

I'm trying to get Pusher to work with my Laravel application. I have a private channel, user is authenticated and connects to it. When I send a test message from Pusher Debug Console, I receive the entry on my client.

I'm having an issue with sending an event to pusher from my L5 app. The event is triggered, and in my L5 log I see the following:

[2017-03-02 13:07:23] local.INFO: Broadcasting [App\Events\xyz] on channels [private-xyz_35] with payload:
{
    "message": {
        "user": "35",
        "code": "KKKK1111"
    },
    "socket": null
}  

My .ENV file and broadcasting config are all configured correctly. When I trigger the event, i don't see an API Message in my Pusher Debug Console.

Can anyone point me out what am I doing wrong here?

This is my event:

<?php

namespace App\Events;

use Illuminate\Broadcasting\Channel;
use Illuminate\Queue\SerializesModels;
use Illuminate\Broadcasting\PrivateChannel;
use Illuminate\Broadcasting\PresenceChannel;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Broadcasting\InteractsWithSockets;
use Illuminate\Contracts\Broadcasting\ShouldBroadcast;

class xyz implements ShouldBroadcast
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    /**
     * Create a new event instance.
     *
     * @return void
     */

    /**
     * Only (!) Public members will be serialized to JSON and sent to Pusher
    **/
    public $message;


    public function __construct($message)
    {
        $this->message = $message;
    }

    /**
     * Get the channels the event should broadcast on.
     *
     * @return Channel|array
     */
    public function broadcastOn()
    {
        return new PrivateChannel('xyz_' . $this->message['user']);
    }
}

via Petar-Krešimir