I think Matip has looked abit more out of form, but TBF West Ham make it very difficult, I just think with their physical play and set pieces, it might have been worth to put Konate in for strength and power.
I thought Fab had a poor game as well, they were breaking through our MF to easily.
Allisson also had a poor game, with West Ham being renowned for their set piece work, it just appeared we hadn't really planned for them? like letting them get around Allisson, one of VvD or Matip should have been in there pushing Antonio & co out the way, Allisson should have just gone through them to clear the ball, if they all get clattered, the ref usually gives a free kick to the GK anyways.