Why have steps when using ssqueezepy to calculate instantaneous frequency?

[wsf1990]

1. I'm using ssqueezepy to calculate signal's instantaneous frequency, The method like below:

   Tx, Wx, ssq_freqs, scales, *_ = ssq_cwt(data, ('gmw', {'beta': 2, 'gamma': 3}), order=0, padtype='wrap', fs=fs)
   ridge_idxs = extract_ridges(Tx, scales, penalty=0.5)
   frequencies = ssq_freqs[::-1][ridge_idxs[:, 0]]  # this is the result

2. The result like below:

3. I think this method can get the correct result, but the result have some steps which not smooth.So what cause this?Which parameters should change?

Thanks!

[OverLordGoldDragon]

I'll handle on SE.