Yoast SEO sitemap subdirectory 404

in multisite subdirectory setup

loading /blog/sitemap_index.xml got white page. and /blog/main-sitemap.xsl got 404.

but loading /sitemap_index.xml works fine and /main-sitemap.xsl works too

i think /blog/sitemap_index.xml should not request from /blog/main-sitemap.xsl since the plugins is only located at the root directory.

hope you understand thanks in advance.