Why do I get file name instead of document title? (pdf, FM2022)

I don't think it's a bug at all - I just created a simple doc in FM2022 (17.0.8.853) and filled it some Jeff Goldblum lorsum (thanks Jeffsum generator!) and created a PDF by doing File > Save as PDF (which uses the Publish engine under the hood). Without giving it any File Info, the PDF appears in Edge and Acrobat Pro with the file name as the title. When I added the title in the FM file's File Info screen and created a new PDF (same Save As PDF), I got the text I had entered appearing in the various PDF views.

The Title field was already set, and I have now updated it and restarted FrameMaker. But it doesn't matter, I still get the file name.
And, in Acrobat Reader, the Document Properties' Title field is correct - as set in FrameMaker.
(The FM2019 version of the same document has the desired Title in the PDF's title bar.)