When you generate sitemap from drush commands drush:rebuild or drush:regenerate, you will see that generated sitemaps could has another host in custom links (by default, it is host "default").
It is related to that $base_url was removed from settings.php in Drupal 8 and when you do commands from drush, you will get by default host = "default", not your current host name of site. This is issue not related to actions with generation sitemap from UI xmlsitemap module, only from drush commands.
Add few custom links for indexation from UI. For example: /contact
Run drush:rebuild or drush:regenerate from command line of your application.
Check generated sitemaps and will see you custom link as: http://default/en/contact
Refactor code of XmlSitemapGenerator and apply correct hostname to custom links.
Active
1.4
Code
This is still an issue in using Drupal 11.1.5. The URL is set to default, not the actual URL.
I am sure I missed something?
Hello @netgeek123
Did you try to use changes as in proposed patch #2?