MultiLanguage and 404

Hey.

I recently started using codeigniter4 and have a little MultiLanguage problem.
I have 2 languages planned on my site, English and Russian.
I followed the instructions described here.

I created translation files.

Code:

/app
    /Language
        /en
            app.php
        /ru
            app.php

My APP config:

PHP Code:

public $defaultLocale = 'en';
public $negotiateLocale = false;
public $supportedLocales = ['en', 'ru']; 


In the route I have written:

PHP Code:

$routes->get('{locale}/', 'Home::index'); 


When i add to route {locale} and i have trouble with 404.

Any non-existent page of the first level always gives the 200th code, like "localhost/dsa".
Any non-existent page should give the 404th code?
This problem is not observed if I do not use {locale}, 
Iit’s critical for me that each language has a unique prefix.
Sorry if I indistinctly described the problem, English is not my main language.

If you need clarifying information, I am ready to provide.