  The survival of the quantum spin Hall edge channels in presence of an
external magnetic field has been a subject of experimental and theoretical
research. The inversion of Landau levels that accommodates the quantum spin
Hall effect is destroyed at a critical magnetic field, and a trivial insulating
gap appears in the spectrum for stronger fields. In this work, we report the
absence of this transport gap in disordered two dimensional topological
insulators in perpendicular magnetic fields of up to 16 T. Instead, we observe
that a topological edge channel (from band inversion) coexists with a
counterpropagating quantum Hall edge channel for magnetic fields at which the
transition to the insulating regime is expected. For larger fields, we observe
only the quantum Hall edge channel with transverse resistance close to $h/e^2$.
By tuning the disorder using different fabrication processes, we find evidence
that this unexpected $\nu=1$ plateau originates from extended quantum Hall edge
channels along a continuous network of charge puddles at the edges of the
device.
