Update WooCommerce order status generates 2 identical confirmation mails

Hi all, I have created a plugin in the past. This plugins changes the default order status in WooCommerce. This always worked fine, but now it’s causing a problem.

The issue is; when this plugin is activated customers get 2 identical confirmation mails for their order. When I deactive it this doesn’t happen. So it must be caused by this plugin, but I don’t get it why… Does somebody have an idea?

<?php
/**
 * Plugin Name: Custom Order Status
 * Plugin URI: ...
 * Description: Change order status by default to 
 * Version: 1.0
 * Author: ...
 * Author URI: ...
 */

#<editor-fold defaultstate="collapsed" desc="Default Status as Pending">
function action_woocommerce_payment_complete( $order_id ) {  
      if( ! $order_id ) return;
        $order = wc_get_order( $order_id );  
        $order->update_status( 'wc-pending' );
};  
           
// add the action  
add_action( 'woocommerce_payment_complete', 'action_woocommerce_payment_complete', 10, 3 );  
#</editor-fold>
?>

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