WordPress Customizer allow line break

The only way I was able to make it work was that:

functions.php

function test_customizer( $wp_customize ) {
    $wp_customize->add_setting( 'themeslug_text_setting_id', array(
        'capability' => 'edit_theme_options',
        'default' => 'Lorem Ipsum',
        'sanitize_callback' => 'sanitize_textarea_field',
    ) );

    $wp_customize->add_control( 'themeslug_text_setting_id', array(
        'type' => 'text',
        'section' => 'title_tagline', // Add a default or your own section
        'label' => __( 'Custom Text' ),
        'description' => __( 'This is a custom text box.' ),
    ) );
}

Front (ex. index.php)

<?php $themeslug_text_setting_id = get_theme_mod('themeslug_text_setting_id');
    if ($themeslug_text_setting_id) { 
        echo nl2br( esc_html( $themeslug_text_setting_id ) );
} ?>

The sanitize_textarea_field is fundamental here.