wp_menu_nav shown only on single page

Hi, have some troubles with wp_menu_nav on my site

as i see on travelify/library/structure/header-extensions.php we have code for menu

	<?php
		if ( has_nav_menu( 'primary' ) ) {
			$args = array(
        'menu'              => 'primary',
				'theme_location'    => 'primary',
				'container'         => '',
				'items_wrap'        => '<ul class="root">%3$s</ul>'
			);
			echo '<nav id="main-nav" class="clearfix">
					<div class="container clearfix">';
				wp_nav_menu( $args );  

			echo '</div><!-- .container -->
					</nav><!-- #main-nav -->';
		}
		else {
			echo '<nav id="main-nav" class="clearfix">
					<div class="container clearfix">';

				wp_page_menu( array( 'menu_class'  => 'root' ) );
			echo '</div><!-- .container -->
					</nav><!-- #main-nav -->';
		}
	?>

they show menu only on single page, on home, category is empty menu. when i do echo has_nav_menu( ‘primary’) on these pages, im get 1 . have no idea what a problem here.