How to get “string” away – replaced with “nothing” [closed]

The woocommerce_template_single_title() function calls to a template that uses this code:

the_title( '<h1 class="product_title entry-title">', '</h1>' );

So it is just the product title, there is nothing that could go wrong here.

Check if you did not mess up output buffer, try using the_title function from above instead of ob and see if that makes a difference.