  We report on the appearance of a structure at low energies in the
photo-electron momentum distribution of the hydrogen atom exposed to two-color
counter-rotating bi-circular laser fields. These structures, which arise due to
AC-Stark shifted resonances, break the three-fold symmetry, typical for the
$\omega-2\omega$ bi-circular fields. We discuss the physical origin of this
structure in terms of partial-wave interference between direct ionization
channels and a resonant pathway, that passes through the AC-Stark shifted state
and show how the underlying Rydberg state population depend on the field
strength and pulse duration.
