For anyone reading this thread, you can also create a link to your liking by using the filter described in this thread.
For example, here is what I did. (I did not use ACF to register my field, just PHP.)
add_filter( 'meta_field_block_get_block_content', function ( $content, $attributes, $block, $post_id ) {
$field_name = $attributes['fieldName'] ?? '';
if ( $field_name === '_my_url_field') {
$content = '<a href="' . $content . '">' . $content . '</a>';
}
return $content;
}, 10, 4);
Of course, replace _my_url_field with your own field’s name.