Amplitude value after a Discrete-Time integration calculation?
I figured it out coming back to basic maths, I  was making a mistake when integrating my sin function that Matlab block wasn't doing, I was missing behind the $\omega$ variable

$$ve[n] = -B \cdot \cos[\Omega\cdot n] = \int A\sin(\omega\cdot t) = (A/\omega)(-\cos(\omega\cdot t)) + Const$$ $$\mathbf {B = (A/\omega) }$$