Dear Kwant community, I have been studying the integer quantum Hall effect using the Kwant software, through which I computed the longitudinal and transverse conductance of a central sample (without disorder) in a four-terminal setup. I model the central device, which is subject to a strong magnetic field, as a square of lateral length, L. Both the sample and the four ideal leads are described by a square-lattice tight-binding model with nearest-neighbor hoppings. By computing the transverse conductance as a function of the Fermi energy, so that the first two Landau levels are crossed, I observe the expected behavior: the conductance appears quantized in integer steps of e²/h. However, upon zooming in on each of the two plateaus, I notice that the conductance does not converge immediately to the expected value. Instead, it exhibits a rippling effect, which seems to be dependent on the leads' cross-section, L_{Lead}. This phenomenon is illustrated in the attached .pdf file, and I have also included the code used to evaluate the conductance. My question is whether this behavior is a numerical issue, or if it is expected within the context of charge transport simulations in four-terminal setups. Thank you in advance, Henrique Veiga