Help Unregistering a Core Block Type in Gutenberg
Everything works for me with allowed_block_types hook. Example: add_filter( ‘allowed_block_types’, ‘my_function’ ); function my_function( $allowed_block_types ) { return array( ‘core/paragraph’ ); } You can insert the above code to your functions.php file to a custom plugin. It removes all blocks except the Paragraph block. More examples here https://rudrastyh.com/gutenberg/remove-default-blocks.html