Sitemap best practices for multilingual websites: should I list my URLs in each language or is it enough to use rel = "alternate" + hreflang?

I am working on the site maps of a multilingual website and I have doubts about the best practices to refer to each language version of a page.

For a little background, the website refers to around 20,000 places with community comments and descriptions. The website is available in 5 languages ​​(; …)

At the moment, my site map only refers to pages in English and on the site map for each page that I specify for each language (as well as English) as recommended by Google.

In Google Search Console, I see that approximately 75% of pages with valid coverage are described as "indexed, not submitted on Sitemap", which makes me think that the alternative link with the hreflang attribute is not enough to "send" the Google page to index it.

Should I list the pages in the 5 languages ​​on my site map and use them too? in each link?