wp_list_pages() links are replaced with custom field values from custom posts

Hi guys!
So, basically I have built custom post type and I have added few custom fields by ACF plugin (for example – <product name>). In functions.php, where I am registering this custom post type, in arguments array, I have excluded all supported fields (title,editor,thumbnail etc.) so I could add my ACF custom fields and make custom post title from custom field values(for example – “My custom post title” is replaced with “<product name>”)

I am using code below to change custom post title to custom field values:

/*	Set post title from meta field	*/
	function new_title($title) {
		global $post, $post_ID;

		if(get_field('auto_marka')){
			$title = get_field('marka') . ' | ' . get_field('modelis') . ' ' . $title;
		}

		if(get_field('prece_nosaukums')){
			$title = get_field('prece_nosaukums') . ' | ' . get_field('modelis') . ' ' . $title;
		}

		return $title;

	}

	add_filter('the_title', 'new_title');

The problem is that, when I am trying to search for products in search page, all the navigation menu’s links are replaced with first custom post search result’s title (For example: “Home” is replaced with – <product name>Home)

Below is navigation menu code, that is used in search.php:

<?php if ( has_nav_menu( 'primary-menu', 'mytheme' ) ) { ?>
									<?php wp_nav_menu( array( 'container' => false, 'theme_location' => 'primary-menu', 'fallback_cb' => 'display_home', 'exclude' => 'home' ) ); ?>
								<?php } else { ?>
									<?php wp_list_pages('title_li=&depth=4&sort_column=menu_order'); ?>
								<?php	} ?>

I have big headaches with this, because I am trying to fix this problem for days, so I would really appreciate your help! :@

P.S.I have added a screen-shot below so you could understand the situation better.

https://img607.imageshack.us/img607/9383/98682975.png

With best wishes,
Ricards