Wrong urls on XML sitemap

And i’ve got this error message:

This page contains the following errors:

error on line 3 at column 6: XML declaration allowed only at the start of the document
Below is a rendering of the page up to the first error.

Just have a look: https://internet-pr-beratung.de/sitemap_index.xml

@baynado please share how you solved the issue, my site map is gone after update to 1.7.

ok so I had to go to SEO Dashboard and “Reset Default Settings”, then re-do my settings again. Now the site map is working.