Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
Are you using a cache plugin? If yes, it could be caching the sitemaps, which would slow the generation (and also causing issues indexing it).
If you are using a cache plugin, you might want to add the following cache exceptions:
/(.*)sitemap(.*).xml
/(.*)sitemap.xsl
Looking forward to helping you. 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.