does not work on some categories

Hi,

I have problems entering the discount on three categories, the hourglass turns but nothing happens, this is the error I see,

2024-01-08T01:35:41+00:00 CRITICAL Uncaught TypeError: Unsupported operand types: string - float in /var/www/vhosts/xxxxxxxxxxx.com/httpdocs/wp-content/plugins/woo-product-category-discount/cd-admin.php:475
Stack trace:
#0 /var/www/vhosts/xxxxxxxxxxxxxx.com/httpdocs/wp-includes/class-wp-hook.php(324): wpcd_save_discount()
#1 /var/www/vhosts/xxxxxxxxxxxxx.com/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#2 /var/www/vhosts/xxxxxxxxxxxxxx.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#3 /var/www/vhosts/xxxxxxxxxxxx.com/httpdocs/wp-admin/admin-ajax.php(188): do_action()
#4 {main}
  thrown in /var/www/vhosts/xxxxxxxxxx.com/httpdocs/wp-content/plugins/woo-product-category-discount/cd-admin.php on line 475

Thanks