Multisite page cache purging

Hi!

I am having trouble flushing front page cache of a multisite main site. On the front page there are posts listed from different subsites and I am trying to find a way to flush the page cache whenever a subsite is publishing or updating a post.

I tried using w3tc_flush_url() function inside the save_post hook, but it does not seem to work for the main site (subsite’s front page is purged automatically on post update and is working fine):

function clear_cache_network( $post_id ) {
    if ( wp_is_post_revision( $post_id ) )
        return;

    // Flush main site front page cache
    if ( function_exists('w3tc_flush_url') ) {
        w3tc_flush_url( get_home_url(1, '/') );
    }
}
add_action( 'save_post', __NAMESPACE__ . '\\clear_cache_network', 10, 3 );

w3tc_flush_url( get_home_url(1, '/') ) flushes the cache perfectly when called from the main site though. Am I missing something or is there another way to achieve what I described?

Thanks for your attention!