Random Products are not showing the amount of post which i include in posts_per_page - wordpress

Question

Random Products are not showing the amount of post which i include in posts_per_page
this is the criteria which i used to call products
$cpsc_args = array(
'post_type' => 'product',
'posts_per_page' => 8,
'order' => 'desc',
'orderby' => 'rand',
'tax_query' => array(
array(
'taxonomy' => 'pwb-brand',
'field' => 'term_id',
'terms' => $cpsc_term_id_display,
'operator' => 'IN'
)
)
);
$cpsc_query = new WP_Query( $cpsc_args );
now the results amount of products are shuffling sometimes it shows 7 products or 8 sometimes or 9 on every refresh.
here is the plugin file code where i loop the plugin.
<?php
/*
Plugin Name: Sultan Custom Brands
Description: This will Display All the Posts or any Post type as you want.
Version: 1.0
Author: Sultan Gillani
Author URI: https://nya.smyckendahls.se/
Text Domain: sultan-cpsc-plugin
*/
//include_once('functions.php');
function form_create($attr){
$cpsc_terms = get_terms( array(
'taxonomy' => 'pwb-brand',
'hide_empty' => false,
) );
$attr = shortcode_atts(array(
"cpsc_posts_per_page" => -1,
"cpsc_order" => "DESC",
"cpsc_orderby" => "date",
"cpsc_terms_show" => $cpsc_terms[0]->slug,
"cpsc_columns" => 4
),$attr);
$cpsc_term_id = get_term_by( 'slug', $attr['cpsc_terms_show'], 'pwb-brand');
$cpsc_term_id_display = $cpsc_term_id->term_id;
$cpsc_args = array(
'post_type' => 'product',
'posts_per_page' => $attr['cpsc_posts_per_page'],
'order' => $attr['cpsc_order'],
'orderby' => $attr['cpsc_orderby'],
'tax_query' => array(
array(
'taxonomy' => 'pwb-brand',
'field' => 'term_id',
'terms' => $cpsc_term_id_display,
'operator' => 'IN'
)
)
);
$cpsc_query = new WP_Query( $cpsc_args );
?>
<div class="woocommerce columns-<?php echo $attr['cpsc_columns']; ?>">
<?php
wc_get_template_part('loop/loop','start');
if ( $cpsc_query->have_posts() ) {
while ( $cpsc_query->have_posts() ) {
$cpsc_query->the_post();
wc_get_template_part('content','product');
}
// Restore original Post Data
wp_reset_postdata();
}
wc_get_template_part('loop/loop','end');
?>
</div>
<?php
}
add_shortcode('cpsc_code','form_create');
function cpsc_vc_element(){
$brand_arr = [];
$cpsc_terms_data = get_terms( array(
'taxonomy' => 'pwb-brand',
'hide_empty' => false,
) );
$brand_arr['Select The Brand'] = '';
foreach($cpsc_terms_data as $cpsc_term_data){
$brand_arr[$cpsc_term_data->name] =$cpsc_term_data->slug;
}
vc_map(
array(
'name' => __('Brand Query Builder'),
'base' => 'cpsc_code',
'category' => __('Test Shortcodes'),
"icon" => "icon-wpb-woocommerce", // Simply pass url to your icon here
"content_element" => true,
'admin_enqueue_css' => array('/wp-content/plugins/brand_plugin/cpsc.css'),
'params' => array(
array(
"type" => "number",
"holder" => "div",
"class" => "cpsc_plugin_posts_per_page",
"heading" => __( "Posts Per Page", "sultan-cpsc-plugin" ),
"param_name" => "cpsc_posts_per_page",
"value" => "0",
"description" => __( "Enter the number of post to display.", "sultan-cpsc-plugin" )
),
array(
"type" => "dropdown",
"holder" => "div",
"class" => "cpsc_plugin_order",
"heading" => __( "Order", "sultan-cpsc-plugin" ),
"param_name" => "cpsc_order",
'value' => array(
__( 'Orber By', "sultan-cpsc-plugin" ) => '',
__( 'Ascending', "sultan-cpsc-plugin" ) => 'ASC',
__( 'Descending', "sultan-cpsc-plugin" ) => 'DESC',
),
"description" => __( "Order Your Post", "sultan-cpsc-plugin" )
),
array(
"type" => "dropdown",
"holder" => "div",
"class" => "cpsc_plugin_orderby",
"heading" => __( "Order By", "sultan-cpsc-plugin" ),
"param_name" => "cpsc_orderby",
'value' => array(
__( 'Select The Orber With', "sultan-cpsc-plugin" ) => '',
__( 'Date', "sultan-cpsc-plugin" ) => 'date',
__( 'ID', "sultan-cpsc-plugin" ) => 'ID',
__( 'About the Author', "sultan-cpsc-plugin" ) => 'author',
__( 'Title', "sultan-cpsc-plugin" ) => 'title',
__( 'Modified', "sultan-cpsc-plugin" ) => 'modified',
__( 'Random', "sultan-cpsc-plugin" ) => 'rand',
__( 'Comment Count', "sultan-cpsc-plugin" ) => 'comment_count',
__( 'Menu Order', "sultan-cpsc-plugin" ) => 'menu_order',
__( 'Menu Order & title', "sultan-cpsc-plugin" ) => 'menu_order title',
),
"description" => __( "Order by the criteria.", "sultan-cpsc-plugin" )
),
array(
"type" => "dropdown",
"holder" => "div",
"class" => "cpsc_plugin_terms_show",
"heading" => __( "Brands", "sultan-cpsc-plugin" ),
"param_name" => "cpsc_terms_show",
'value' => $brand_arr,
"description" => __( "All Brands", "sultan-cpsc-plugin" )
),
array(
"type" => "textfield",
"holder" => "div",
"class" => "cpsc_plugin_columns",
"heading" => __( "Columns", "sultan-cpsc-plugin" ),
"param_name" => "cpsc_columns",
"value" => "4",
"description" => __( "", "sultan-cpsc-plugin" )
),
)
)
);
}
add_action('vc_before_init','cpsc_vc_element');
?>

Answer 1

Var_dump your:
$cpsc_terms[0]->slug
My quess is that the slug varies per page request? If so, the query will be based on a different term_id each request (if random). And term_id 1 might have 7 posts related, where term_id 2 has f.e. 9 posts related, etc. Hence the number of posts shown.