Hello,
Thank you for your query and we are so sorry about the trouble this must have caused.
If there are any issues reported on your URLs that prevent them from being indexed, you can see them in the coverage section report of your GSC:
https://support.artlogic.net/hc/en-gb/articles/360016851260-Google-Search-Console-errors-and-coverage-issues
Please send a screenshot here so we can check as well. You can use this tool to upload the image file and send the link here.
We really look forward to hearing back from you. Thank you.
Hello,
Thank you for contacting Rank Math support and we apologize for the inconvenience.
The zero discovered pages do not mean that Google is ignoring your sitemap or that your pages are not being indexed. It simply means that Google has already found your pages from another source, such as a link from another site or a social media post. Your sitemap is just one of the ways that Google can discover your pages, but it is not the only one. As long as your pages are being indexed, you don’t need to worry about how they are discovered. Your sitemap is still useful because it helps Google find your new or updated content faster.

As you can see from the screenshot above, Google has already indexed quite a lot of your posts, so you do not need to worry about the sitemap showing zero discovered pages.
You can read more about this issue here: https://rankmath.com/kb/zero-discovered-urls-through-sitemap/.
We hope this helps you understand the issue better. If you have any other questions or concerns, please let us know.
Thank you for choosing Rank Math.
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.