Hello,
Thank you for contacting the support and sorry for any inconvenience that might have been caused due to that.
According to Google guidelines : All formats limit a single sitemap to 50MB (uncompressed) or 50,000 URLs. If you have a larger file or more URLs, you must break your sitemap into multiple sitemaps. You can optionally create a sitemap index file and submit that single index file to Google.
With Rank Math you can divide the sitemap based on the number of links. To do so, please navigate to Rank Math > Sitemap Settings. You can read more about it here: https://rankmath.com/kb/configure-sitemaps/#links-per-sitemap
Hope that helps and please do not hesitate to let us know if you need our assistance with anything else.
Thank you
