[Plugin: WordPress SEO by Yoast] sitemap: XML Parsing Error

i had google xml sitemaps plugin but tried the xml feature of this plugin (wordpress seo plugin by the amazing mr yoast)

i went to check the xml sitemap and i got this error:
XML Parsing Error: XML or text declaration not at start of entity
Location: https://www.glogoodz.com/sitemap_index.xml
Line Number 1, Column 9:

i tried it with a few settings on and off and it didn’t change. i tried turning ‘google xml sitemap’ plugin on and off and that didn’t change anything. the sitemap from that plugin is at
https://www.glogoodz.com/sitemap.xml

any ideas what might be wrong?

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