My WordPress site has 65 posts, but Rank Math's sitemap was only showing 49. The remaining 16 posts were invisible to Google. Here's how I fixed it with a 30-line PHP file.
The Problem
Rank Math Free limits post-sitemap.xml to a fixed number of entries. When I published post #50, it silently pushed post #1 out of the sitemap. Google eventually deindexed the missing pages.
The Fix: ww-sitemap.php
I created a PHP file in my WordPress root that generates a sitemap dynamically from the database, excluding any URLs already in Rank Math's sitemap (to avoid duplicates):
<?php
header('Content-Type: application/xml; charset=utf-8');
require_once(__DIR__ . '/wp-load.php');
$posts = get_posts(['post_type' => 'post', 'post_status' => 'publish', 'posts_per_page' => -1]);
// Get existing sitemap URLs to avoid duplicates
$xml = @file_get_contents(home_url('/post-sitemap.xml'));
preg_match_all('/<loc>([^<]+)<\/loc>/', $xml, $m);
$existing = array_flip($m[1] ?? []);
echo '<?xml version="1.0" encoding="UTF-8"?>';
echo '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">';
foreach ($posts as $post) {
$url = get_permalink($post);
if (!isset($existing[$url])) {
$mod = get_the_modified_date('Y-m-d', $post);
echo "<url><loc>{$url}</loc><lastmod>{$mod}</lastmod></url>";
}
}
echo '</urlset>';
Then I submitted ww-sitemap.php in Google Search Console alongside the existing sitemap_index.xml.
The Result
- Before: 49 URLs in sitemap, 16 posts invisible to Google
- After: All 65 posts discoverable
- Bing picked up the missing pages within 48 hours via IndexNow
Lessons Learned
- Always verify your sitemap contains all your pages — don't assume the plugin handles it
- Dynamic PHP sitemaps are a valid fallback when plugin settings aren't accessible
- Submit supplementary sitemaps in GSC — you can have multiple
Site: watchwalls.pro — an Apple Watch wallpaper resource where I discovered this problem.
