Sitemap issue with Polylang default language

Hi!

I’m having problems with the sitemap generation in a site which uses the Polylang plugin. The site is translated into three languages (Spanish, Catalan and English). The sitemap generation works in all the languages except the default one (Spanish), which only shows two entries:

https://example.com/sitemap.xml:

https://example.com/
https://example.com/blog/

Both the Catalan and English versions show all the entries (pages and posts):

https://example.com/en/sitemap.xml:

https://example.com/en/
https://example.com/blog/
https://example.com/en/about/
https://example.com/en/contact/
(... rest of the pages and posts, omitted for brevity... )

Any idea why this is happening?

Thanks in advance