BroadcastAs and BroadcastWith appear to not be working

Hi - this is linked to getting pusher events working on my app and trying many things to resolve.

In my event class I've tried renaming an event that uses the trait shouldBroadcast. I've set a value in the event using the broadcastAs() method and also some data (for testing) in the broadcastWith() method.

When the event fires to pusher I don't see the correct name or the additional data in what's sent to pusher as I thought it would.

I've tried to look through the api documentation to see how these methods work and struggling to find the right reference but all the guides seem to suggest the methods are there to be used.

That then has led me on the path of whether I've completed upgrades properly. The app started 10 years ago using Laravel 5.1 and has evolved now to using Laravel 10. Each upgrade I've followed the guidance but I don't see many references to events and broadcast that could break the use of broadcasting - plus I know it works as I can see the event in pusher.

Here's my event:

<?php

namespace App\Events;

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

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

    public $message;

    /**
     * Create a new event instance.
     */
    public function __construct($message)
    {
        Log::info('ButtonClicked event fired');
        $this->message = $message;

    }

    /**
     * Get the channels the event should broadcast on.
     *
     * @return array<int, \Illuminate\Broadcasting\Channel>
     */
    public function broadcastOn(): array
    {

        return [
            new Channel('channel-name'), //changed from the real one
        ];
    }


    /**
     * Get the data to broadcast.
     *
     * @return array<string, mixed>
     */
    public function broadcastWith(): array
    {
        \Log::info('Broadcasting data: ', [
            'message' => $this->message,
        ]);


        return [
            'message' => $this->message,
            'dateSent' => now()->format('Y-m-d H:i:s')
        ];
    }

    /**
     * Get the name of the event to broadcast.
     *
     * @return string
     */
    public function broadcastAs(): string
    {
        \Log::info('Broadcasting data: ', [
            'message' => $this->message,
        ]);

        return 'button.clicked';
    }

}

Why would the event ignore broadcastAs and broadcastWith? and where in Laravel are these methods used (so I can do some more research)

Thank you