Hello,
I do not claim to be an expert in Avia, and I cannot say I know for certain how you created the page content on the page you link.
However, when I logged in to edit that page, I clicked on the .. block? and it opened a modal popup. Inside that popup was the GD Shortcode builder button.
I clicked on it and setup a GD Search shortcode, and clicked insert.
It inserted fine, and once I saved the page it rendered fine on the frontend.
Whatever was done before appears to have mangled (technical term) the shortcode and made it not work.
In the future, if that happens again, I would avoid that method of insertion, and simply copy the shortcode from the shortcode builder window instead of using the “Insert Shortcode” button.
Can you explain how it happened? Maybe that will help us understand how we can make it work better with Avia.