SEO plugin and sitemap/crawl issues

Hi,

I have some issues re: htp://www.sellhousefastadvisor.co.uk/

(1) The homepage doesn’t appear in the sitemap:
https://www.sellhousefastadvisor.co.uk/sitemap_index.xml

(2) I’m getting crawl errors in Google Webmaster Tools:
Sitemap contains urls which are blocked by robots.txt:
https://www.sellhousefastadvisor.co.uk/post-sitemap.xml

Any help would be much appreciated.

Thanks

https://www.ads-software.com/extend/plugins/wordpress-seo/