[Kwant] Modifying Magnetic Field

Hello. I would like to verify the Landau Levels in the Hall conductance of graphene nanoribbons. The code works for conductance, band structure and Hall conductance, but I would like to know why the plateaus are not visible. Also, I would like to know why the plot of wavefunctions does not return to the existence of edge states, which should be for zigzag graphene nanoribbons. Attached is the code. Regards, James