Doesnt work with WooCommerce?

I have a WordPress + WooCommerce instalation, and I needed the Maintenance mode for a few weeks until we can start selling again. Anyway, I installed the plugin, set it On, but it doesn’t work.

If I go to the URL preview it works: https://tiendadeharrypotter.com.ar/?maintenance-preview

But if I remove the query string from the URL: https://tiendadeharrypotter.com.ar/ I still see the ecommerce.