  Due to Landau quantization, the conductance of two-dimensional electrons
exposed to a perpendicular magnetic field exhibits oscillations that generate a
fan of linear trajectories when plotted in the parameter space spanned by
density and magnetic field. This fan looks identical irrespective of the
electron dispersion details that determines the field dependence of the Landau
level energy. This is no surprise, since the position of conductance minima
solely depends on the level degeneracy which is linear in flux. The fractal
energy spectrum that emerges within each Landau band when electrons are also
exposed to a two-dimensional superlattice potential produces numerous
additional oscillations, but they too create just linear fans for the same
reason. Here, we report on conductance oscillations of graphene electrons
exposed to a moir\'e potential that defy this general rule of flux linearity
and attribute the anomalous behavior to the simultaneous occupation of multiple
minibands and magnetic breakdown.
