When creating a URL for the current page
$urlGenerator->generateFromCurrent();
the URL is created with the locale, if the locale is the default Locale Middleware redirects to the URL without the locale, in middleware Dispatcher returns a request object with the locale.
In the route middleware, the locale is again passed to the generator through the CurrentRoute class and so on in a circle )
When creating a URL for the current page
$urlGenerator->generateFromCurrent();the URL is created with the locale, if the locale is the default Locale Middleware redirects to the URL without the locale, in middleware Dispatcher returns a request object with the locale.
In the route middleware, the locale is again passed to the generator through the CurrentRoute class and so on in a circle )