unexplainable simulink behavior encountered

Hello everyone I am encountering unexplainable behavior on simulink. I am working on designing an estimation strategy for vehicle parameters in simulink. So my overall model includes a 14-DOF vehicle model, a subsystem for driver input, a subsystem for the sensors (where signals are sampled from the 14-DOF model and pass along with added Gaussian noise), and finally the estimation strategy itself which is composed of several modules, each producing a single estimate of a vehicle dynamic parameter. The 1st screenshot is part of the sensors subsystem, where a Gaussian noise might/might not be added to 4 wheel speed signals using a manual switch, BTW the Gaussian noise for now is ZERO, so no noise at all. That is not the point; the point is that the highlighted part in the picture (highlighted in blue) should not have an effect what so ever on the normalized-root-mean-squared calculated in one of the estimation modules. but for some reason deleting that part or keeping it changes the calculated NRMS. More over, If I delete the entire sensors subsystem, and creating a new one like in the 2nd picture, the calculated NRMS is completely different. Can anyone please explain why this is happening? even though there is no Gaussian noise connected and everything else is exactly the same.