Yoast Sitemap Is not Removed after installing Rank Math

Hello,

Thank you for contacting us and sorry for any inconvenience that might have been caused due to this issue.
Kindly follow the steps stated in this article to remove Yoast data from your site: https://rankmath.com/kb/remove-yoast/

Now regarding your robots.txt file:

The robots.txt file is saying, “Contents are locked because a robots.txt file is present in the root folder.”

Rank Math makes it possible to edit your robots.txt file right inside your WordPress dashboard, by creating a virtual file. If you prefer to edit your robots.txt file using Rank Math, you’ll need to delete the actual robots.txt file from your website’s root folder using an FTP client or File Manager in CPanel. Then follow the steps in this KB article: https://rankmath.com/kb/how-to-edit-robots-txt-with-rank-math/#num-2-1-navigate-to-edit-robots-txt.

Finally, you can refer to this guide on how to properly configure your sitemap using Rank Math: https://rankmath.com/kb/configure-sitemaps/.

Let us know how this goes.

Thank you.