the first thing to check is to make sure the step size is the same between the two models. I am assuming it is, but it is good to check just in case. If the step size is the same, it is possible that the number of iterations is not correct, although for your model, it looks like the number of iterations should be 1, in which case their should be no issues.
initial conditions should work with this workflow, although if you change the initial conditions in the original model, you'd need to rerun the workflow advisor to update the model.
Would you be willing to share your model? (we can do that seperately through a secure means instead of you posting it here)