The expert's product is rendering with the default product template, which is a shop page. Open the product in your Shopify admin, find Theme template in the right-hand column, and choose expert. Save, and the page becomes a profile: portrait, role, details, bio and a Book button, with no price and no cart.
To do it for many products at once, select them in the product list and use the bulk editor to set the template column.
While you are there, uncheck the Shop channel on expert products so they do not appear in the Shop app as items for sale. See Expert profile pages.