Why doesn't Google process the Sitemap?

Question

Google

Please take a look: https://turundusinfo.ee/sitemap1-50000.xml

I can't figure out what mistakes were made when compiling this map.
Now there are 50,000 entries.
If you add about 25000, then sometimes the URLs are processed, and sometimes not.
I tried to add the current version by the link to the Search Console and gave out "Failed to process the Sitemap file".

I don’t understand which service to use to check the sitemap code and find errors.
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Here is a new https://turundusinfo.ee/sitemap1.xml exactly with the example on https://support.google.com/webmasters/answer/18366. ..but still throws an error without explanation

Answer 1

Sitemap should not contain more than 50000 URLs. Do the second one. And their index. Documentation .

I don’t understand which service to use to check the sitemap code and find errors.