Will linmod linearize away a constant force?

Hello, I have an open-loop and closed-loop model of a control system, which we call from a script to obtain margins and time response, utilizing the linmod command. This has worked well for some time.

However, recently we needed to add a term that looks like a constant acceleration/force, which our control system has to contend with. When run WITHIN the simulink model, it has the expected effect from a step command - it does not start at zero, but some offset value determined by the added term.

The problem we're having is when we call this from the script, the linmod command appears to be "linearizing away" the new term, and the results end up matching the models we had before the change that do not include the new term.

Is there a way around this? Some way to tell linmod not to "linearize away" our constant force we've added?

Or, perhaps something more subtle is going on?