It is actually a chinese 12k (the naniwa 12k was a bit too expensive).
I did stopped and checked at 50 strokes, then 100 then 150 with all strokes using no pressure, just keeping the blade flat.

In general, I don't cut corners, I lapped the hones, I go slow and I am careful. That's why it's frustrating.
My game plan for this week end is to start over and to stop only when I get the right result at the right level using all tests at my disposal.

If that still does not work, I'll have it done by a honemeister and ask him (or her - are there any?) what was done to the razor. It's all fun anyway!