Dynamic Block not rendering in frontend

[Der-Alex]

Hi there. I created a dynamic block using the create-block script:
npx @wordpress/create-block@latest --namespace my-namespace --no-plugin my-block --variant dynamic
This creates a my-block folder inside my theme's assets/blocks folder.

In my theme's functions.php I register all my blocks like so:

function my_namespace_blocks_init() {
    $directory = __DIR__ . '/assets/blocks';
        
    // get all subfolders inside assets/blocks
    $scanned_directory = array_diff( scandir( $directory ), array( '..', '.' ) );

    foreach ( $scanned_directory as $dir ) {
        register_block_type(
	    $directory . '/' . $dir,
	    array(
		'render_callback' => 'my_namespace_render',
	    )
	);
    }
}
add_action( 'init', 'my_namespace_blocks_init' );

My block's render.php file looks like this:

<?php
function my_namespace_render( $attr ) {
	return '<p>Hello worlds!</p>';
}

For testing purposes I left the other files as they were created by the script. In the full site editor the "My Block" block is available and can be added to the page and gets rendered in the backend. But nothing gets rendered in the frontend. I tested if the render.php gets loaded and changed the content to basic html:

<p>Hello worlds!</p>

This works. I also tried to echo and die inside the render callback function. The callback function simply doesn't get called. I double checked that the callback function name is correct.

Is there anything missing to make the render callback function work? Thanks in advance.

EDIT:

Calling the render callback function inside register_block_type function directly works as well:

        register_block_type(
	    $directory . '/' . $dir,
	    array(
		'render_callback' => function() { return "<p>Hi!</p>"; },
	    )
	);
	...

[Der-Alex]

Okay it seems that the render.php file gets loaded or included after register_block_type is called. So having the callback function inside the render.php file cannot work. When I add include_once $directory . '/' . $dir . '/render.php'; the callback function would work but doing this feels wrong.

Is it a known bug that you cannot use the callback function inside the render.php file?