Filament dynamic RichEditor field returns 'undefined' when creating a new record

I’m building a dynamic form in FilamentPHP where ContentType stores field definitions in JSON. I created a trait to map each field into a Filament component like this:

trait BuildsDynamicFields
{
    protected static function mapField(array $field): Component
    {
        $path = "body." . $field['name'];
        $label = $field['label'] ?? Str::headline($field['name']);
        $rules = $field['rules'] ?? null;

        $applyRules = function ($component) use ($rules) {
            if ($rules) {
                foreach (explode('|', $rules) as $rule) {
                    $component = $component->rule($rule);
                }
            }
            return $component;
        };

        return match ($field['type']) {
            'richtext' => $applyRules(
                RichEditor::make($path)
                    ->label($label)
                    ->statePath($path) // already added
            ),
            'markdown' => $applyRules(
                MarkdownEditor::make($path)
                    ->label($label)
                    ->statePath($path) // already added
            ),
            default => TextInput::make($path)->label($label),
        };
    }

    protected static function buildDynamicSchema(?ContentType $type): array
    {
        if (!$type) {
            return [];
        }

        return collect($type->fields ?? [])
            ->map(fn ($field) => self::mapField($field))
            ->toArray();
    }
}

Then I use this trait inside my ContentResource:

class ContentResource extends Resource
{
    use BuildsDynamicFields;

    public static function form(Form $form): Form
    {
        return $form->schema([
            Forms\Components\Section::make('Information')
                ->schema([
                    Forms\Components\Select::make('content_type_id')
                        ->options(ContentType::query()->pluck('name', 'id'))
                        ->required()
                        ->reactive()
                        ->afterStateUpdated(fn ($state, callable $set) => $set('body', [])),
                ]),

            Forms\Components\Section::make('Body')
                ->schema(fn (Forms\Get $get) => self::buildDynamicSchema(
                    ContentType::find($get('content_type_id'))
                ))
                ->hidden(fn (Forms\Get $get) => empty($get('content_type_id'))),
        ]);
    }
}

Example ContentType->fields JSON:

[
  {
    "name": "content",
    "type": "richtext",
    "label": "Content",
    "rules": null,
    "default": null,
    "placeholder": "the body of the article"
  }
]

• When creating a new record, the RichEditor component renders but only shows "undefined". Any input I type is not saved (always null).
• When editing a record, the same form works correctly, and the text is saved without issues.

I already tried adding .statePath($path) on the RichEditor and MarkdownEditor, but the problem remains.

How can I make the RichEditor or MarkdownEditor not show "undefined" on create, and ensure the value is properly stored inside the body column?