File Upload Component - save() not called?

Hi there

I am trying to create a first File Upload component with Livewire (using Livewire 3 Beta 8). I just followed along the official docs for Getting Started, Components and Uploads. I have no prior experience with Livewire.

The upload works (pretty magically), but the save() function doesn't seem to be called and I can't understand why 🤷🏻‍♂️

I've created a minimal demo with the UploadFiles component right on the welcome view: https://phpsandbox.io/e/x/w6bou?layout=EditorPreview&defaultPath=%2F&theme=dark&showExplorer=no&openedFiles=

Here are some code details, but you can browse the whole app on the phpsandbox link above:

Livewire Component - UploadFiles.php

<?php

namespace App\Livewire;

use Livewire\Attributes\Rule;
use Livewire\Component;
use Livewire\WithFileUploads;

class UploadFiles extends Component
{
    use WithFileUploads;

    #[Rule(['files.*' => 'pdf|max:20480'])]
    public $files = [];

    public $iteration = 0;

    public function save()
    {
        // this function doesn't seem to be called on upload?
        dd("save reached");

        // Store files in temp directory
        foreach ($this->files as $file) {
            $file->store('files');
        }

        // Reset Upload Form
        $this->files = null;
        $this->iteration++;
    }

    public function render()
    {
        return view('livewire.upload-files');
    }
}

Rendered view of the component -upload-files.blade.php

<div>
    <form wire:submit="save">
        <div
            x-data="{ uploading: false, progress: 0 }"
            x-on:livewire-upload-start="uploading = true"
            x-on:livewire-upload-finish="uploading = false"
            x-on:livewire-upload-error="uploading = false"
            x-on:livewire-upload-progress="progress = $event.detail.progress"
        >
            @error('files.*') <span class="error">{{ $message }}</span> @enderror

            @if($files)
                Just Uploaded:<br />
                @foreach ( $files as $file )
                    <a href="{{ $file->temporaryUrl() }}" target="_blank">File</a><br />
                @endforeach
            @endif

            <input type="file" wire:model="files" name="files" id="upload{{ $iteration }}" multiple>

            <!-- Progress Bar -->
            <div x-show="uploading">
                <progress max="100" x-bind:value="progress"></progress>
            </div>

            <button type="submit" :disabled="uploading">Upload files</button>
        </div>
    </form>
</div>

The component is embeded in the welcome view like this:

<livewire:upload-files />

Livewire and Alpine scripts should be automatically injected, as I am reading in the Livewire Docs.

Even when I rename the save() function the upload seems to work, so I am guessing the use WithFileUploads makes that work even without explicitly defining it. Changing the <form wire:submit="save"> to wire:submit="somethingelse" and renaming the function in the component also didn't help.

What am I missing?

Thanks a lot for helping out. Aaron