Hello,
Thank you for contacting the support, and sorry for any inconvenience that might have been caused due to that.
Could you please try to refresh the sitemap by following this video guide?
https://i.rankmath.com/pipRDp
If that resolves the issue, then it might be your sitemap is still heavily cached.
https://rankmath.com/kb/exclude-sitemaps-from-caching/
Let us know how that goes. Looking forward to helping you.
Thanks for your reply Jeremy.
I did watch https://i.rankmath.com/pipRDp and folowed the instructions but nothing has changed and the issue remains.
I use WP Rocket for cache and I had already added the code snippet
Settings > WP Rocket > Advanced Rules> Never Cache URL(s).
/(.*)sitemap(.*).xml
/(.*)sitemap.xsl
But again this has not resovled the issue unfortunately.
Hello,
We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WordPress logins and some of the URLs that are not being included in the sitemap, in the designated Sensitive Data section.
Please do take a complete backup of your website before sharing the information with us.

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:
https://wordpress.org/plugins/temporary-login-without-password/
You can use the above plugin in conjunction with the WP Security Audit Log to monitor what changes our staff might make on your website (if any):
https://wordpress.org/plugins/wp-security-audit-log/
We really look forward to helping you.
Hello,
I was able to check that you have added the canonical URL manually in the Advanced tab of the meta box:

Rank Math automatically sets the canonical URL as the page’s URL when the canonical URL field is left empty. If you enter an URL manually then your category will be treated as duplicate content and will not be included in the sitemap.
I remove the canonical URL from the Advanced tab’s canonical field for this page: https://www.australiannetworkentertainment.com.au/sydney-comedians/ and it is now being included in your sitemap:

Please edit your pages and remove the URLs from the canonical URL field to fix the issue.
Hope this helps. Let us know if you need any other assistance.
Thanks very much for your help Jaideep.
So should you only insert the canonical URL in the Advanced tab, if Google shows there is a duplicate page?
Hello,
A Canonical URL is needed to avoid duplicate content issues. For example, you could have the same product listed on multiple pages on your website. In order to avoid confusion for the search engines, you can inform them about the original content with the help of a Canonical URL.
You should only add it manually when you want to set some other page’s URL as the canonical URL of your page. Otherwise, just leave it empty and Rank Math will take care of it.
Hope this helps. Let us know if you need any other assistance.
Thanks.
Thanks again for you assistance
Hello,
We are super happy that this resolved your issue. 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.