if ( has_blocks( $post->post_content ) ) {
$relatedpostsfound = 0;
$blocks = parse_blocks( $post->post_content );
foreach ($blocks as $block) {
if (( 'core/block' === $block['blockName'] ) || ( 'core/group' === $block['blockName'] )) {
$block_blocks = parse_blocks( get_post( $block['attrs']['ref'] )->post_content );
foreach ($block_blocks as $block_block) {
if ( $block_block['blockName'] === 'acf/related-posts' ) { $relatedpostsfound = 1; }
$block_block_innerblocks = $block_block['innerBlocks'];
foreach ($block_block_innerblocks as $block_block_innerblock) {
if ( $block_block_innerblock['blockName'] === 'acf/related-posts' ) { $relatedpostsfound = 1; }
}
}
}
if ( $block['blockName'] === 'acf/related-posts' ) { $relatedpostsfound = 1; }
}
}