[Resolved] Cannot switch currency back to default upon checkout

<?php
    /* WPML WooCommerce: Change currency back to default upon checkout 
    *   Issue:         Visitor gets charged selected currency amount in original currency, causing a 25% loss in sales.
    *   Resolution:    Hook before checkout page gets displayed to force the currency back to default.
    */
    function wa_woocommerce_revert_currency_on_checkout($currency) {

        error_log("Currency: ".$currency);
        
        if (is_checkout() && $currency != "CAD") { // Check if current page is checkout and currency is not CAD
            return "CAD"; // Set currency to CAD. TODO: Get default site currency dynamically.
        } else {
            return $currency;
        }

    }; add_filter('wcml_client_currency', 'wa_woocommerce_revert_currency_on_checkout', 10, 1);
?>