Trajectories crossing observation plane

Running hybrid_MC as at today (with cut lowered to 3 GeV), a sizeable fraction (> 20 %) of the showers fail because some trajectories exceed the observation plane and go below ground. gdb output:

#7  corsika::ShowerAxis::getProjectedX (this=this@entry=0x7fff07926b30, p=...) at /home/ka/ka_iap/ka_xxxxxx/corsika/corsika/detail/media/ShowerAxis.inl:109
109         return getX(projectedLength);
(gdb) p p
$3 = (const corsika::Point &) @0x7fff07926320: {<corsika::BaseVector<phys::units::dimensions<1, 0, 0, 0, 0, 0, 0, 0> >> = {quantityVector_ = {
      eigenVector_ = {<Eigen::PlainObjectBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> >> = {<Eigen::MatrixBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> >> = {<Eigen::DenseBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> >> = {<Eigen::DenseCoeffsBase<Eigen::Matrix<double, 3, 1, 0, 3, 1>, 3>> = {<Eigen::DenseCoeffsBase<Eigen::Matrix<double, 3, 1, 0, 3, 1>, 1>> = {<Eigen::DenseCoeffsBase<Eigen::Matrix<double, 3, 1, 0, 3, 1>, 0>> = {<Eigen::EigenBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> >> = {<No data fields>}, <No data fields>}, <No data fields>}, <No data fields>}, <No data fields>}, <No data fields>}, m_storage = {m_data = {array = {1116.5140376118152, 490.03453658239732, 6368384.0377964033}}}}, <No data fields>}},
    cs_ = {<std::__shared_ptr<corsika::CoordinateSystem const, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<corsika::CoordinateSystem const, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = 0x173b1f70, _M_refcount = {_M_pi = 0x173aa4b0}}, <No data fields>}}, <No data fields>}

Note that 6368384.0377964033 < mean Earth radius. The error seems to occur only for the magnetic tracking (default settings).