Incorrect http header content-type: “” (expected: “application/xml”)

Hello,

Thank you for contacting the support, and sorry for any inconvenience that might have been caused due to that.

Can you please follow these steps?

1. Flush the Sitemap cache by following this video screencast:
https://i.rankmath.com/pipRDp

2. Exclude the Sitemap files of the Rank Math plugin in your caching plugin. The cache could be via a plugin or from the server. For plugins or Cloudflare, please follow this article:
https://rankmath.com/kb/exclude-sitemaps-from-caching/

Let us know how that goes. Looking forward to helping you with this one.

Hello,

We have replied to your other ticket with the same issue. If you have further questions about this concern, please continue there to avoid duplication.

Looking forward to helping you.

Thank you.