In matlab stable, in simulink unstable?

Hello there

I am doing a project for my Systems dynamics Controls class and I am required to build a controller for a system given some requirements. After constructing a PID controller(added two zeros to the system), I saw that my system was stable and met the requirements for some range of gain. I When I use the step command in matlab I get a desirable response, but in simulink, even though I used the same of everything, I still get an unstable system. Also I know the step command in matlab is defaulted as unit step, but my final value is not 1. I checked everything but I still cannot figure out what I did wrong. Thank you for help

here's my matlab code

C1 = 6;
C2 = 5; 
C3 = 12;
M = 1;
K = 120;
B = 2*C3;
b = 0.9*M;
Ka = 1;

Gp = tf(C2,[10 10 0]);
Ga = tf(C1,[1 6]);
As = tf([b],[1 B K]);
U = 62.7;
Cs = zpk([-2+1i -2-1i],[],1);
G = (feedback(Gp*Ga*Cs*U,As));
rlocus(Gp*Ga*Gc*As)
figure
step(G)