wp_footer issue

wp_footer() is the action hook to add scripts, and is needed for that reason.
https://codex.www.ads-software.com/Function_Reference/wp_footer
https://codex.www.ads-software.com/Plugin_API/Action_Reference/wp_footer

your problem might be with whatever plugin or code you are using for the snowfall effect, unless the effect is part of your child theme.

Hi..

Please remove below code from customizer.php file.

<?php
add_action('wp_head', 'snowfall_effect1');
function snowfall_effect1() { ?>
    <script type="text/javascript">
        jQuery(document).ready(function(){
            jQuery(document).snowfall({
                flakeCount : 100,
                flakeColor : '#fff',
                flakeIndex: 999999,
                minSize : 1,
                maxSize : 10,
                minSpeed : 2,
                maxSpeed : 3,
                round : true,
                shadow : false,
            });
        });
    </script><?php
} ?>

Save the changes.

Thanks.

Thanks @weblizar_support

Most Welcome.

Thanks.