Sitemap Issue: “Discovered Pages = 0” When Submitting Main Sitemap

Situation

• Site: brand-new / rebranded domain.
• SEO setup: Perfmatters + Litespeed Cache + Cloudflare.
• Sitemap plugin: initially Yoast SEO → now switched to Rank Math.

Issue

1. When I submit the main sitemap index (domain.com/sitemap_index.xml) in GSC:
   → Status shows “Success,” but Discovered URLs = 0.
2. When I submit individual post/page sitemaps (e.g., page-sitemap.xml, post-sitemap.xml):
   → Discovered URLs show normally.

So, the URLs exist and are crawlable, but GSC isn’t pulling them from the sitemap index.

Possible Causes (what I’ve checked)

• Caching/CDN (but sitemap file is accessible directly).
• Plugin difference (Yoast vs Rank Math).
• Temporary Google indexing issue?

Main Question

• Why does Google show 0 discovered pages for the main sitemap index but normal numbers for individual sitemaps?
• Could this affect overall indexing or rankings, or is it just a reporting glitch in GSC?

It's just a reporting glitch in GSC, it happens to me every time I submit my sitemap.
Just submit sitemap_index.xml and let it be. Google will take care of the rest. You don't have to submit individual post/page sitemaps.

If your sitemap index passes validation online, don’t stress, GSC reporting quirks happen more often than people realize

Happens pretty often with new domains — GSC sometimes shows 0 discovered for the index but still crawls the child sitemaps fine. As long as your sitemap index validates and the individual maps are accessible, you’re good. It won’t hurt rankings or indexing; it’s just a reporting bug on Google’s side. Best thing is submit the index once, leave it, and focus on content + links.

Sounds like a reporting quirk Google sometimes shows 0 for the sitemap index even if the individual sitemaps are being crawled.