Why am I getting www in the URLs on production but not in dev?

[Livijn]

I am adding all my URLs like this atm:

$this->sitemap = Sitemap::create();
// ...
$this->sitemap->add(
    Url::create($route)
        ->setLastModificationDate($modificationDate ?? now())
        ->setChangeFrequency($changeFrequency)
        ->setPriority($priority)
);

For some reason all of my URLs are set to www in prod environment. However, locally they are rendered without the www-prefix. I have set all my pages canonical URLs to omit the www so I need this gone from the sitemap aswell.

I don't have www in my .env in prod. It doesn't matter if I visit the sitemap using www. Also, using route('home') in prod returns the url without www.

How can I remove the www in production?

[Livijn]

It was due to visiting the URL with www. It didn't seem like it was at first due to the fact that I am caching the results.