Hi, I order a month ago 3 touch screen 42mm, for my surprise the replacements don't work, and after trying the 3 touch I started to read this thread.

I think is firmware related, I get one of the replacement to work, what I did is desolder the original IC ubicated in the flex of the original touch, this is the only IC in the touch screen, I reballed the IC and install it in one of the new touch screen, and after that new touch with the original IC work, unluckily the touch don't work perfect, sometimes gets crazy and sometimes dont work at all. I will rework again the IC and test.

So if you have a shop in your town that repairs touch disease they probably can fix your apple watch with the cheap chinese replacements.