Inconsistency between the results generated by IMRPhenomXPHM and IMRPhenomD

[NeoWon]

Hi there, I am using pycbc to generate waveforms for giving BBH parameters with different approximations, but I found that the results produced by IMRPhenomXPHM and IMRPhenomD are quite different.

when I use the following code:

hp1, _ = get_td_waveform(approximant="IMRPhenomXPHM",
mass1=30,
mass2=30,
spin1z=0.5,
spin2z=0.5,
spin1x = 0.,
spin2x = 0.,
delta_t=1.0/2048,
f_lower=20,
coa_phase = 0,
distance=600)

hp2, _ = get_td_waveform(approximant="IMRPhenomD",
mass1=30,
mass2=30,
spin1z=0.5,
spin2z=0.5,
spin1x = 0.,
spin2x = 0,
delta_t=1.0/2048,
f_lower=20,
coa_phase = 0,
distance=600)

the phase evolution of the two outputs do not match with each other. I have PyCBC 2.2.0 installed.

Could anyone help me to figure out the problem?

[NeoWon]

BTW, the plot code is

plt.figure(figsize=(10, 6))
plt.plot(hp1.sample_times, hp1, label='IMRPhenomXPHM',color='red')
plt.plot(hp2.sample_times, hp2, label='IMRPhenomD',color='blue',linestyle='--')
plt.xlim([-1.2,-0.05])
plt.xlabel('Time (s)')
plt.ylabel('Strain')
plt.title('Gravitational Wave from Binary Black Hole Merger')
plt.legend()
plt.show()