EDIT: I googled, and found it; yes, I'm pretty confident, I use a "trick" (don't ask) so that I freehand sharpen at very repeatable angle, and I don't have this lack-of-abrasion issue on other stones.
(that difference would it make anyway - at the risk of an ugly double negative, it doesn't matter where I'm not getting abrasion)
marcelo, mizuyama, that is the stone from korin? they also have a togiharu house brand 1k that looks like a rebranded king deluxe.
Hi there bugbear, what i meant is that your stone could be abrading, but not at the right place (the edge). If you are getting a black slurry in your stone, it is abrading metal. Now, you'll only need to adjust the angle to get it right. If you paint your edge using a sharpie pen, you may see if you are hitting the edge. If you are positive the stone is not abrading anything, you might give Maxim a head's up and see what's going on.
Hi Panda. Yes, Mizuyama is the stone from Korin. The problem is that i don't think you'll like it very much as it is slower than JNS 1k. The feedback is great in my opinion ( it feels grainier/sandier than King). Never used Togiharu, but it sure looks like King!