sitemap index issue

hello
i am using latest yoast free version on my site.
i have notice from last 4 days a huge drop in traffic.
i analyses that the sitemap is not accepting my google.
have a loon on these snapshots please
http://prntscr.com/ad3ndy
http://prntscr.com/ad3nzf
please help me resolve this issue

https://ww.wp.xz.cn/plugins/wordpress-seo/