On my site, https://test.antikvarijatknjiga.hr, I use Woocommerce Waitlist plugin which gives ability to place oneself on a waitlist for the product.
This works well when the archive page is generated after initial search, but, when changing sort order, the add-to-waitlist button disappears. Regular add-to-cart for products that are in-stock works fine.
For example, https://test.antikvarijatknjiga.hr/?s=krle&post_type=product
That archive page looks good, it has “Pridruzite se listi cekanja” button in case product is out of stock. But, if we switch to in-stock first, then this option disappears.
All this works fine with WPSOLR disabled.