Import WPML products with same SKU - - Product import export plugin for WooCommerce by WebToffee (https://www.webtoffee.com/product/product-import-export-woocommerce/)

functions.php

<?php // Please do not copy this line
add_filter('wt_product_import_allow_same_sku', '__return_true');

add_filter('wc_product_has_unique_sku', 'wt_fix_wcml_sku_issue', 10, 3);

function wt_fix_wcml_sku_issue($sku_found, $product_id, $sku) {
    return false;
}