[WooCommerce] Product tabs missing

Hello, I have been configuring my new e-shop based on newest WooCommerce plugin, I had problems with displaying Add to cart button in variable products, solved this by adding <?php wp_head(); ?> to my header, but after adding this, all my product tabs disappeared. Same for variable or single products. Testing on this product.

https://koralky.aldeco.cz/produkt/duhove-8-mm/

I know its some kind of conflict in wp_head and my head, but dont know where to look. Can somebody give me a clue how to proceed?

Thanks a lot.