I get the following error when I try to implement code block 4.59:

Code to run:

height_pred = pm.sample_posterior_predictive(trace_4_3, 200, m4_3, keep_size=False)

Error:

ValueError: conflicting sizes for dimension 'chain': length 1 on the data but length 4 on coordinate 'chain'

I didn't get any error for previous code blocks in this chapter (chapter 4), and I can't figure out what is causing this error.
Appreciate any help.