Hi there, Davide! Welcome to the forums. 🙂
Good question. Tickets are registered as Products in WooCommerce, which are their own post type. It seems as though your site’s search includes WooCommerce Products in its search parameters, so you’ll want to exclude them.
I found this thread where someone was able to do that with a snippet. I’d give that a shot as a way to exclude WooCommerce Products from being included in your search results.
If that doesn’t work, then perhaps the Search Everything plugin will be a good option. It allows you to exclude specific post types from the WordPress search function.
Cheers!
Geoff