WooCommerce, Tree Table Rate Shipping: Exclude product attributes from the 'Contains' condition.

functions.php

<?php
// Paste everything below this line to your child-theme's functions.php file.

// Exclude product attributes from the 'Contains' condition.
add_filter('woocommerce_attribute_taxonomies', function($taxs) {

    $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 10);
    foreach ($backtrace as $call) {
        if (isset($call['file']) && preg_match('#wc-tree-table-rate-shipping(/|\\\\)tpl.php#', $call['file'])) {
            return [];
        }
    }

    return $taxs;

}, PHP_INT_MAX, 1);