Page Sitemap Image URLS not showing CDN URL After Adding Recommended Code

I have added this code to my child functions.php in an effort to get my images to index correctly with the CDN setup:

/* YOAST CDN SETUP */

add_filter( 'wpcf7_support_html5_fallback', '__return_true' );

function wpseo_cdn_filter( $uri ) {
return str_replace( 'https://markartall.com', 'https://cdn.markartall.com', $uri );
}
add_filter( 'wpseo_xml_sitemap_img_src', 'wpseo_cdn_filter' );

It seems to be working on my post sitemap but not my page sitemap.

Any idea why this would happen?