Hello,
The general breadcrumbs option is for all the pages, posts on the site. If you enabled the special option for the single product title and moved it from breadcrumbs to product content then h1 tag with title appears in the product content https://gyazo.com/ad0cfdc1e161ea75d7d9a28a14fee07f for the single product because this option has more priority, not in the breadcrumbs. Inspect product using the dev tool and you’ll see.
Regards