WooCommerce Subscriptions (Preserve Billing Schedule)

woocommerce-subscriptions-preserve-billing-schedule.php

<?php

/* 
 * By default, WooCommerce Subscriptions will calculate the next payment date for a subscription from the time of the last payment. 
 * This snippet changes it to calculate the next payment date from the scheduled payment date, not the time the payment was actually processed.
 */
 
add_filter( 'wcs_calculate_next_payment_from_last_payment', '__return_false' );