Hey @alanowen,
Thank you for reaching out.
I had a look at the sitemap URL and I’m able to see the 404 as well. However, the non-pretty permalink of your site.co.uk/?sitemap=1 does load the sitemap.
It seems like there is indeed an issue with your permalinks, but I checked your menu on the site and it looks like you don’t have pretty permalinks enabled. I recommend using “postname” as your pretty permalink option. https://yoast.com/help/how-do-i-change-the-permalink-structure/.
It seems that https://www.wholesalebrandedcosmetics.co.uk/?sitemap=1 does work. After trying your suggestion, none of the products would load, so I changed it back to ‘Plain’ and now it works, although https://www.wholesalebrandedcosmetics.co.uk/sitemap_index.xml still has a 404 error?
I would investigate why your pretty permalinks wouldn’t work as having pretty permalinks for your whole site is recommended: https://yoast.com/change-wordpress-permalink-structure/
I just noted that your site runs on a Windows IIS server, it might not directly work as pretty permalinks use your .htaccess file to make things work. Please check with your web host if/how you can make it work. When you don’t have pretty permalinks, it’s normal that /sitemap_index.xml wouldn’t work as it relies on pretty permalinks to work.
This thread was marked resolved due to a lack of activity, but you’re always welcome to re-open the topic. Please read this post before opening a new request.
