ACF Extended is bundled with a custom merged version of the Classic Editor & Disable Gutenberg plugins. This module is a global setting which is applied to all post types.
This module is disabled by default. To enable it, you can use the following code:
add_action('acf/init', 'my_acfe_modules');
function my_acfe_modules(){
// Enable Classic Editor
acfe_update_setting('modules/classic_editor', true);
// Or:
acf_update_setting('acfe/modules/classic_editor', true);
}