why pagination not show up on my site?

that’s weird, my site almost not work with any code, even WP-pagenavi plugin. But when I try it on another site with same theme, it works perfectly.
What’s wrong?? you have any ideals?

this my pagination code :

function wapvn_page_nav() {
    global $wp_query, $paged;
    $total = $wp_query->max_num_pages;
    if(!$total) $total = 1;
    if(empty($paged)) $paged = 1;
    if($total > 1) {
        $out = array();
        if($total > 5) {
            if($paged > 1) $out[] = '[<a class="pagenav" href="' . get_pagenum_link($paged - 1) . '"><<</a>]';
            if($paged > 3) $out[] = '[<a class="pagenav" href="' . get_pagenum_link(1) . '">1</a>]';
            if($paged > 4) $out[] = '<span style="font-weight: bold;">←</span>';
        }
        for ($i = 1; $i < ($total + 1); $i++) {
            if (!($i >= ($paged + 3) || $i <= ($paged - 3)) || $total <= 5) {
                if ($i == $paged) {
                    $out[] = '<span class="page larger"><b>' . $i . '</b></span>';
                } else {
                    $out[] = '<a class="page larger" href="' . get_pagenum_link($i) . '">' . $i . '</a>';
                }
            }
        }
        if ($total > 5) {
            if ($total > ($paged + 3)) $out[] = '<span style="font-weight: bold;">→</span>';
            if ($total > ($paged + 2)) $out[] = '[<a class="pagenav" href="' . get_pagenum_link($total) . '">' . $total . '</a>]';
            if ($total > $paged) $out[] = '[<a class="pagenav" href="' . get_pagenum_link($paged + 1) . '">>></a>]';
        }
        echo '<div class="wp-pagenavi">' . implode(' ', $out) . '</div>';
    }
}

here is my site that pagination not work :
https://wapsaigon.com/

and the site with same theme but works perfectly :
https://hotgame247.comze.com/