Indeed, you can see that filter on the photo's above: the black/copper colored horizontal coil on the left, above the yellow capacitor, and to the right of the white connector.
I did add a ferrite beat myself, because I had them anyway, and also I was fighting noise on my scope at that time.
(Turned out to be the 1200x300 office LED panel attached to the ceiling. Weird, because that was not a china purchase but an expensive one bought from a professional office outfitter. just goes to show: if you pay a lot, you may still get the Chinese crap, just someone else has a big margin for putting on a label)