Force Jetpack to use og:url with http on an https website

The code you used should work.

BTW to me, as the code is not working, the best approach would be to unset the og:url from Jetpack and do it on your own? I’m taking your code and adding mine and editing where necessary:

<?php
/**
 * Change HTTPS to HTTP
 * @param  string $url Default URL.
 * @return string      Modified URL.
 * -----------------------------------
 */
function https_to_http_url( $url ) {
    $url = str_replace('https://', 'http://', $url );
    return $url;
}


/**
 * Altering Jetpack OG URL
 * We're going to strip out the og:url produced by Jetpack.
 * @param  array $tags  Array of Open graph tags.
 * @return array        Modified array of Open graph tags.
 * -----------------------------------
 */
function jetpack_removing_og_url( $tags ) {
    //unset completely, we'll produce our own
    unset( $tags['og:url'] );

    return $tags;
}
add_filter( 'jetpack_open_graph_tags', 'jetpack_removing_og_url' );

/**
 * Add custom og:url
 * Adding our custom Open Graph URL meta tag on our own.
 * -----------------------------------
 */
function wpse233574_custom_og_url() {

    //Jetpack-way to retrieve the URL
    if ( is_home() || is_front_page() ) {
        $front_page_id = get_option( 'page_for_posts' );
        if ( 'page' == get_option( 'show_on_front' ) && $front_page_id && is_home() )
            $url = get_permalink( $front_page_id );
        else
            $url = home_url( "https://wordpress.stackexchange.com/" );
    } else if ( is_author() ) {
        $author = get_queried_object();
        if ( ! empty( $author->user_url ) ) {
            $url = $author->user_url;
        } else {
            $url = get_author_posts_url( $author->ID );
        }
    } else if ( is_singular() ) {
        global $post;
        $url = get_permalink( $post->ID );
    }

    //Modifying the URL for our custom purpose
    $modified_url = https_to_http_url( $url );

    //Finally print the meta tag
    echo '<meta property="og:url" content="'. esc_url($modified_url) .'" />';
}
add_action( 'wp_head', 'wpse233574_custom_og_url' );