Sitemap.xml is obtained without formatting/tree. How to fix?

Question

Create a sitemap

https://2048.zone/sitemap.xml
(the site automatically detects the language, so if you have Russian defined, go to the main page, switch the language to English)

Yandex Webmaster writes that there are no errors.
w3 validator throws an error.
Well, the page itself looks like this:

And in theory it should be like this:

The file was made according to the standards, the encoding is correct.
Tried through generators - the result is the same.
What could be the matter and how to fix it?