Hello,
Thank you for contacting Rank Math, and sorry for any inconvenience caused.
Please note that Google crawls the sitemap and website according to the crawl budget of the website.
The lower number in Discovered URLs that you see in Google Search Console just means that the URLs in the sitemap were already found by Googlebot by other means, instead of via the sitemap. For example, Googlebot may have found the URLs from internal links or possibly from links on another site.
However, please ensure that the sitemaps are excluded from caching:
https://rankmath.com/kb/exclude-sitemaps-from-caching/
Hope that helps.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.