Authoritative source for the title of an article: print or online? The web page for Nature volume 567 issue 7748 lists a comment called "Scientists rise up against statistical significance".  If you click on the link you get an online article with that title, and at the end there is a note saying "Nature 567, 305-307 (2019) doi: 10.1038/d41586-019-00857-9".  But the online article also has a link to a "PDF version" which appears to show the actual layout of pages 305 to 307 with the title "Retire statistical significance".

What is the correct citation for this paper? And why do publishers make our lives difficult?
You appear to have found something quite bizarre: not just this article, but many of the Nature "Comment" articles appear to be titled differently in their HTML and PDF versions!

So, how to sort such a bizarre occurrence out? In my opinion, it's ambiguous whether print or online is "definitive", since many journals do not even bother with a print edition any more, and following a DOI will take you to the HTML version.

Instead, I would revert to first principles on the purpose of citation: to enable a person to find the document that is being referenced.  To this end, I suggest searching online (as somebody who might follow the citation would). Here, one finds that the HTML title predominates (perhaps unsurprisingly), and thus I would recommend using the online title in this case.