Cannot estimate chpi amplitudes slope

Iā€™m working with a raw fif data. I used find_bad_channels_maxwell to find bad channels and compute_chpi_amplitudes trying to compute head position. Well the estimated chpi_amplitudes slopes were all nan. Here is my codes and results. I cannot tell where is wrong.

# Load data
raw = mne.io.read_raw_fif(fpath_fif, allow_maxshield=True, verbose=False)
# Identify bad sensors by maxwell filter
fine_cal_file = os.path.join(PATH_root, 'SSS', 'sss_cal.dat')
crosstalk_file = os.path.join(PATH_root, 'SSS', 'ct_sparse.fif')
raw.info["bads"] = []
raw_check = raw.copy()
auto_noisy_chs, auto_flat_chs, auto_scores = mne.preprocessing.find_bad_channels_maxwell(
    raw_check,
    cross_talk=crosstalk_file,
    calibration=fine_cal_file,
    return_scores=True,
    verbose=True,
)
print('noisy =', auto_noisy_chs)
print('flat = ', auto_flat_chs)
raw.info['bads'].extend(auto_noisy_chs + auto_flat_chs)
# estimate head position
chpi_amplitudes = mne.chpi.compute_chpi_amplitudes(raw, tmin=0, tmax=50)

output:

Reading 0 ... 965999  =      0.000 ...   965.999 secs...
Using 4 HPI coils: 293 307 314 321 Hz
Line interference frequencies: 50 100 150 200 250 300 Hz
Using time window: 142.9 ms
Fitting 4 HPI coil locations at up to 4993 time points (50.0 s duration)
100%
cHPI amplitudes : 4993/4993 [00:12<00:00, 384.66it/s]

Variable chpi_amplitudes:

{'proj': <Projection | SSS, active : False, n_channels : 300>,
 'times': array([18.  , 18.01, 18.02, ..., 67.9 , 67.91, 67.92]),
 'slopes': array([[[nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan]],
 
        [[nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan]],
 
        [[nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan],
         [nan, nan, nan, ..., nan, nan, nan]],

Does head_pos = mne.chpi.compute_head_pos(raw.info, chpi_amplitudes, verbose=True) produce anything useful?