That feature actually comes from the Genesis Framework. Check out the Genesis Demo – https://demo.studiopress.com/genesis-sample/
Here is StudioPress’ link on how to disable it – https://my.studiopress.com/documentation/snippets/scripts/disable-superfish-script/
They have more on their docs pages.
You can always change the responsive setting in your theme (near the bottom) so it activates at a smaller width if you think it will be an issue….Although most people with desktop/laptops are not going to be viewing your site on a browser that small. It can only happen on a desktop/laptop, but the user would have to have their browser shrunk pretty small for it to happen.