'Newest products' recommendation does not work in product feed

In the article it is stated:

We use a “created_at” timestamp that is specific to Klaviyo. This means that when you first sync your catalog, every product in the catalog will have the same “created_at” value, so the newest products recommender will not be useful at first. Once you’ve added some new items to your catalog after the initial sync, you should start to see the expected behavior.

This also means that items will not be prioritized by the recommender just because they’ve been “updated” or have recently come back in stock. This recommender will only prioritize net new products added to your catalog.

But it is not working like described here. I get not the newest products, but recently updated products.