Our quick view template files are almost the same as a single product page template. If you check the file basel/woocommerce/content-quick-view.php, you will see that it uses default WooCommerce hook do_action( 'woocommerce_single_product_summary' ); and it displays the add to cart button the same as on the single product page. So it seems to be a plugin issue since our theme is coded with all standard functions that come with WooCommerce and WordPress.
“Buy now” link is not generated with JS but instead is loaded with default WooCommerce functions. And we didn’t modified woocommerce_template_single_add_to_cart function either.