Adding Association field in Theme Options generate an error 500

[poillic]

Version

• Carbon 3.6.9
• Wordpress 6.8.3
• PHP 8.3.27

Expected Behaviour

I created an association field in Theme options.

What is expected ?
I can select a max of 4 associated element, save them and modified them later.

Actual Behaviour

When I reload the page after saving post, I'm not able to see and edit the previously picked elements.

Minimum code the generate the issue

<?php

use Carbon_Fields\Container;
use Carbon_Fields\Field;

add_action( 'after_setup_theme', 'crb_load' );
function crb_load() {
    require_once( 'vendor/autoload.php' );
    \Carbon_Fields\Carbon_Fields::boot();
}

function register_courseware_post_type() {
	register_post_type('formation', array(
		'labels' => array(
			'name' => 'Formation',
			'add_new' => 'Ajouter une Formation',
			'add_new_item' => 'Ajouter un nouvelle Formation',
			'singular_name' => 'Formation'
		),
		'public' => true,
		'has_archive' => true, /* True to display all formation in a page */
		'rewrite' => ['slug' => 'formation'],
		'show_in_rest' => true,
		'supports' => array('title'),
		'menu_icon' => 'dashicons-welcome-learn-more'
	));
}
add_action('carbon_fields_register_fields', 'register_courseware_post_type');

add_action('carbon_fields_register_fields', function() {
	Container::make('post_meta', 'Courseware Infos')
		->where('post_type', '=', 'formation')
		->add_fields(array(
			Field::make('image', 'courseware_cover', 'Image de couverture')
				->set_help_text( "Resolution 1350x600 pixels" )
		));
});

/* THEMES OPTIONS */
function crb_attach_theme_options() {
    Container::make( 'theme_options', __( 'Theme Options' ) )
        ->add_fields( array(
			Field::make('association', 'pdfre', 'Formation mise en avant')
				->set_max(3)
				->set_types(array(
					array(
						'type' => 'post',
						'post_type' => 'formation'
					)
				))
        ) );
}
add_action( 'carbon_fields_fields_registered', 'crb_attach_theme_options' );

Step to reproduce

• Add the code above in functions.php
• Create one or more "Formation" in backoffice
• In Theme Options pick one or more "Formation" with the association field
• Refresh the Theme Options page

Comments

Error URL : http://localhost:8082/wp-json/carbon-fields/v1/association/?container_id=carbon_fields_container_options_du_theme&options=54%3Apost%3Aformation%3B53%3Apost%3Aformation%3B40%3Apost%3Aformation&field_id=pdfre

This may be a loading issue, association field trying to get data from field not yet loaded ?