I was unable to recreate this same exact issue for another website; for other websites when you screenshot using driver.execute_cdp_cmd("Page.printToPDF", params)
the screenshot stores the entire webpage with no need to scroll - so not sure why it didn't work for Coursera.
So to resolve, I changed the params being passed into this call and the zoom:
driver.execute_script("document.body.style.zoom='90%'")
params = {'landscape': False, 'paperWidth': 12, 'paperHeight': 25}
data = driver.execute_cdp_cmd("Page.printToPDF", params)
This seemed to do the trick.
Code: https://github.com/psymbio/math_ml/blob/main/coursera_pdf_maker.ipynb
PDF: https://github.com/psymbio/math_ml/blob/main/course_1/week_1/practical_quiz_1.pdf
It's sad this doesn't render on GitHub.