C-Block Coding Basics

I try to simulate a 3Phase inverter circuit.
I created a PWM generator in C DLL and it works fine.
However when I add 2 more instances (See shaded here)
No PWM is getting out of the Pins.
I assume that there is some interaction (Unwanted) between the sub circuits X1, X2 X3 which I’m not aware of? Any idea how can this be solved or done correctly?