Colon is Missing In My Website Url in WordPress Shortcode

So I’ve had this shortcode [site_url] working fine until a few days ago, now as I’m trying to use it again and it shows me a https// instead of https://.

I’ve tried using this function:

//Website URL shortcode [site_url]
add_action( 'init', function() {
add_shortcode( 'site_url', function( $atts = null, $content = null ) {
    return site_url();
    } );
} );

And I’ve also tried this one:

    function create_site_url()
{
    return home_url();
}

add_shortcode('site_url', 'create_site_url');

I’ve also tried to check my wp_options table and they are all correct and all have the ":"

I’m currently at a loss to why it stopped working, as I’ve installed no new plugins and made 0 changes. All the older shortcode applications seem to be calling the https://, however any new applications of the same shortcode just pull http//

Anyone got any ideas? Thanks in advance.