Hello,
Thank you for contacting Rank Math, and sorry for any inconvenience caused.
Please make sure that the Categories are set to index, as Rank Math only adds the URLs to sitemap when they are set to index.
You can set the categories to index by going to Rank Math > Titles & Meta > Categories > Enable Category Archives Robots Meta > Check index checkbox > Save
https://rankmath.com/kb/titles-and-meta/#category-archives-robots-meta-custom-settings
Once done, clear your website cache and check the sitemap.
Hope that helps.
Don’t hesitate to get in touch if you have any other questions.
Ahh Yes, that’s it. Thanks for the quick response.
Hello,
We are super happy that your issue is resolved. If you have any other questions in the future, know that we are here to help you.
If you don’t mind me asking, could you please leave us a review (if you haven’t already) on https://wordpress.org/support/plugin/seo-by-rank-math/reviews/#new-post about your overall experience with Rank Math? We appreciate your time and patience.
If you do have another question in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.