Hi,
There seems to be some problem with the simulation setup. If you look at the mag and the phase plots, they don't go hand-in-hand. Near to 0Hz, the mag plot shows a +x dB roll-off, whereas the phase rolls off by -x deg. At 1K the phase plot flattens out, but the mag plot rolls off.
Please check the setup and the measurements.
I think in Gray meyer book there is a mention of the a 3-amp structure for AC analysis, instead of opening the loop using the elements.
Regards,
RDV