According to the company website:
Lotus Biscoff Products are not Kosher certified.
Note: Biscoff brand products, including Lotus Cookies, that are made in Belgium and are imported and sold in the US and Europe do not have a hechsher (kosher certification). Biscoff brand products that are produced for Israeli distribution are kosher and do have a hechsher in many kosher food stores around the world as an import from Israel. Please check products carefully for kosher certification before purchase.
The ingredients panel lists only:
Wheat Flour, Sugar, Vegetable Oils (contains one or more of soy bean oil, sunflower oil, palm oil), Brown Sugar, Leavening (sodium bicarbonate), Soy Flour, Salt, Spice (cinnamon)
What would/could be the concern with uncertified packages? What might the kosher-certifying agency be doing different in the "kosher runs" of the cookie?