Can’t add products / categories to conditions

Awesome plugin, but unfortunately I can’t add dome products and product categories to the calculation conditions. Some of them just won’t be found if I search for them in the given input field. But they definitely exits. If I search for them on the normal WC product overview page, they’re there. Same with the categories. We have polylang installed, but it doesn’t seem to be related to that, because I can find some German, some English and some French products, but not every product that I need there. Alle products and categories I’m trying to add are public…

Thanks in advance