Default cart line item show Total with tax. if you dislike it and want show Total exclude tax instead. you can use snippets code plugin or edit yourtheme/functions.php to add this snippets . After done, logout and login pos again to take effect

add_filter('op_get_login_cashdrawer_data',function($session_response_data){
      $session_response_data['setting']['pos_cart_item_incl_tax_mode'] = 'no';
      return $session_response_data;
},110,1);