functions.php

/**
* usage [thecontent 'id-1234]
* works fine in elementor  
* but not gutenberg
**/

add_shortcode( 'thecontent', function ( $atts ) {
    $a = shortcode_atts( 
        array(
		   'id' => '1',
	   ), 
	   $atts );
     $post = get_post($a['id']); 
     $content = apply_filters('the_content', $post->post_content); 
     echo $content; 
  } ) ;