XML Validaion Results

Hi There,

I seem to have issues with the sitemap generated and linking this to Google search console where I get the error: Unsupported file format

I have created the sitemap and it loads fine from in the browser. However, in validating via https://www.xml-sitemaps.com/ we get the error: Incorrect http header content-type: “text/html; charset=UTF-8” (expected: “application/xml”)

The site has a Sucuri firewall – and I have whitelisted the sitemap_index.xml file. I have also cleared cache and regenerated the permalinks (as suggested in other posts) but still face this issue.