Generated paths contains language prefix

It would be easy enough to strip the path prefix from the URL.

You can get the path prefixes with:

$prefixes = \Drupal::config('language.negotiation')->get('url.prefixes');

So... just loop through these and strip from signature_url if it starts with that + /.

Does someone want to create a patch/MR?

Here is fix for the language prefix

Here is a fix compatible with the latest versions of the module

When adding this patch it conflicted with issue: 3375732, so I combined both into a new patch for those who need it.

All patches in this issue change the download link from the actual security.txt file to the signature file.