Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
The url you have shared doesn’t seem to appear in the category sitemap. Please head over to WordPress Dashboard > Rank Math > Titles & Meta > Categories and make sure you haven’t checked the “noindex” option in the robots section.
If you have, please uncheck it, clear your website cache and reload the sitemap index. Let us know how it goes.
We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WP logins in the designated Sensitive Data section.
It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead: