Try using a different mask for each layers height.
Don’t plug the same mask to two or more layer heights.
Though I don’t see if you already have used different masks for each layer, I’m guessing by the look of wires.
Edit: Whatever it is it’s %90 because of the way you have setup the heights maps. I’m seeing very unnecessary setups.
Try to do a cleaner and more simple setup and it will work. From there expand it to what you already have and you will discover the problem.