The Further Reading or Endnotes section lists books that don't exist, sometimes "published by" my own publisher. Why?

Earlier versions gave the AI your publisher's name and no rule about inventing sources, so it sometimes made up plausible-sounding works. As of version 1.9.3 the source-listing sections may only cite works that genuinely exist and are well known; when the AI is unsure of a specific title it recommends by kind instead ("a field guide to…"), and any entry that attributes a work to your own publisher or to you is removed automatically. The same rule applies to the references generator. Regenerate the section (Edit → Regenerate section) after updating, and always give Further Reading a final read before publishing: an AI recommendation list is a starting point, not a verified bibliography.