What keywords did you use? Dumb TV gives zero hits.
It's a category, "Geen Smart TV", under TV's. There are several for sale up to 55".
https://www.bol.com/nl/nl/l/42-inch-tv-s-zonder-smart-functi...
This Sony might be an option: https://www.bol.com/nl/nl/p/sony-bravia-professional-fw-55bz...
loading story #50235379
loading story #50232456