FOX - WooCommerce Currency Switcher Professional

Plugin URL: https://wordpress.org/plugins/uni-woo-custom-product-options/

To your current child wp theme file functions.php add next code:

add_filter('uni_cpo_in_cart_calculated_price', function ($price_calculated, $product, $filtered_form_data) {
    if (class_exists('WOOCS') AND /* !is_shop() AND !is_singular() */) {
        global $WOOCS;
        if ($WOOCS->is_multiple_allowed) {
            $currrent = $WOOCS->current_currency;
            if ($currrent != $WOOCS->default_currency) {
                $currencies = $WOOCS->get_currencies();
                $rate = $currencies[$currrent]['rate'];
                $price_calculated = $price_calculated / $rate;
            }
        }
    }

    return $price_calculated;
}, 99, 3);

add_filter('uni_cpo_nov_variable_value', function ($price, $product_data, $variables, $nov) {
    if (class_exists('WOOCS') AND /* !is_shop() AND !is_singular() */) {
        global $WOOCS;
        if ($WOOCS->is_multiple_allowed) {
            $price = $WOOCS->woocs_exchange_value(floatval($price));
        }
    }
    return $price;
}, 99, 4);