This is on 2.5.0.
The admin confirmation URL in the email has subfolder duplicated. like
https://www.example.com/subfolder/subfolder/u/confirm-admin/key.
I’m looking at
https://github.com/discourse/discourse/blob/master/app/mailers/admin_confirmation_mailer.rb#L12
it appears to call something called confirm_admin_url, but I can’t find where that’s defined.
I’m not sure where to look to see if it’s a bug or some configuration issue (but this is the only place this problem is showing up).