Another menu problem ( Bootstrap Nav Walker)

Hello everyone,

I know there’ve been a lot of such questions but I really cannot handle my problem.
I use a Bootstrap menu + Nav Walker class.
Now I am trying to integrate the Polylang for the first time and I have a lot of problems, namely, the menu stays always German. I have 3 and have created for them 3 menus.

I’ve read the topic above and have tried the code above but my PHP is not so good and it didn’t really work.
I suppose it’s problem with my menu registering function.

Here’s my code:

<?php
add_action( 'after_setup_theme', 'wpt_setup' );
    if ( ! function_exists( 'wpt_setup' ) ):
        function wpt_setup() {
            register_nav_menu( 'primary', __( 'Primary navigation', 'wptuts' ) );
        } endif;

function wpt_register_js() {
    wp_register_script('jquery.bootstrap.min', get_template_directory_uri() . '/js/bootstrap.min.js', 'jquery');
    wp_enqueue_script('jquery.bootstrap.min');
}
add_action( 'init', 'wpt_register_js' );
function wpt_register_css() {
    wp_register_style( 'bootstrap.min', get_template_directory_uri() . '/css/bootstrap.min.css' );
    wp_enqueue_style( 'bootstrap.min' );
    wp_enqueue_style( 'my_template', get_template_directory_uri() . '/style.css' );
}
add_action( 'wp_enqueue_scripts', 'wpt_register_css' );        

// Register custom navigation walker
    require_once('wp_bootstrap_navwalker.php');
?>

and HTML:

<nav class="navbar navbar-default" role="navigation">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </button>
          <h1><a class="navbar-brand" href="<?php echo esc_url( home_url( '/' ) ); ?>"><img src="<?php echo get_stylesheet_directory_uri(); ?>/img/" alt ="" /></a></h1>
        </div>
        <div class="collapse navbar-collapse navbar-ex1-collapse">
          <?php /* Primary navigation */
          wp_nav_menu( array(
               'primary',
			'depth' => 1,
			'container' => false,
			'menu_class' => 'nav navbar-nav',
			//Process nav menu using our custom nav walker
			'walker' => new wp_bootstrap_navwalker())
			);
			?>
        </div>
      </nav>

I would be really grateful for any help!

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