This problem happens on Google Chrome but is also on the Mac, so I am not entirely sure if it is a Mac related issue or Chrome issue.
For some webpages, such as https://redux.js.org/introduction/getting-started Google Chrome can print it out as a PDF, but the first highlighting using Preview would show the highlighting is off. This has been happening for more than a year:
It doesn't happen if it is printed by Safari, but Safari sometimes has some issue such as the content column quite narrow. Is there a way to make it print out suitable for highlighting if it is on Chrome? It might be a Google Chrome issue or it might be somehow related to how macOS support printing but as a PDF file. Since printing as PDF is particular to Mac but not on Windows, so I am asking this on Ask Different.