I have the same problem in HFSS, when you define a ferrite, it asks the saturation magnetic field.
If you make magnetic bias with internal magnetic filed of 0 A/m, HFSS will use the saturation magnetic field you have already defined (I mean the ferrite is biased even if you put 0 A/m for the internal magnetic field in definition of magnetic bias excitation).
I guess that HFSS uses "saturation magnetic field + interanl bias" because by changing both of the parameters the simulation results will change.
Does anybody has any idea about the ferrite defining and so on?
Thanks