MultiBuffer Shadertoy Porting

Hi guys, I'm trying to porting this Shadertoy: https://www.shadertoy.com/view/wdsfzN into Max but I'm experiencing some problem.

In Buffer A I've replaced U with outColor and pos with jit_in.texcoord

In Buffer B, Q is outColor and p become jit_in.texcoord, same for Buffer C.

And in the main Image, fragColor is outColor and pos jit_in.texcoord

What I'm experiencing seems to be a coordinate issue but I'm not sure and I can't figure it out what I'm missing.

Any help will be much appreciated!