Interesting results if you apply rebuild
step= 5.82077e-011 Deriv= -4.15993 Finite Diff= 0.90625
step= 1.45519e-011 Deriv= -4.15993 Finite Diff= 1.75
step= 3.63798e-012 Deriv= -4.15993 Finite Diff= 23
step= 9.09495e-013 Deriv= -4.15993 Finite Diff= 52
step= 2.27374e-013 Deriv= -4.15993 Finite Diff= 456
step= 5.68434e-014 Deriv= -4.15993 Finite Diff= 352
step= 1.42109e-014 Deriv= -4.15993 Finite Diff= 5248
step= 3.55271e-015 Deriv= -4.15993 Finite Diff= 8192
step= 7.27596e-012 Deriv= -44.2222 Finite Diff= 11.125
step= 1.81899e-012 Deriv= -44.2222 Finite Diff= 21
step= 4.54747e-013 Deriv= -44.2222 Finite Diff= 46
step= 1.13687e-013 Deriv= -44.2222 Finite Diff= 276
step= 2.84217e-014 Deriv= -44.2222 Finite Diff= 304
step= 7.10543e-015 Deriv= -44.2222 Finite Diff= 3072
step= 1.77636e-015 Deriv= -44.2222 Finite Diff= 14848
step= 4.44089e-016 Deriv= -44.2222 Finite Diff= 3072
step= 1.11022e-016 Deriv= -44.2222 Finite Diff= 155648
step= 2.77556e-017 Deriv= -44.2222 Finite Diff= 294912