I created a website using WP by WPSinhala help but
I did the all things correctly and also installed rankmath plugin.
I really appreciate if you can help me on this matter!
Remove the current Site maps And Add a Page site map. I had the same issue but it was solved once I submit a Page sitemap.xml and It Covers all pages of my website https://prnt.sc/1rmcaco Check this out.
Also I have forgot Few things Use Yoast SEO And generate a site map using it This will help to it https://yoast.com/help/xml-sitemaps-in-the-wordpress-seo-plugin/ and Then Remove current sitemaps completely. then add Page Site map to search console Hope that will fix also request indexing again after you submit new sitemaps. (Just my opinion and the way I fixed it)