Bug?: I opened a 18 page pdf (attached) in the latest version of Publisher without saving it. I selected pages 13, 14, and 15, clicked on the duplicate icon and only 14 and 15 duplicated. I tried this with several existing pdf documents and had the same issue. When I immediately saved the new document in native format, and tried duplicating the same pages, it worked correctly. Don't know if this matters to you or not. :-)
Suggestion: When you click the icon to add a page you are asked where you want to add it "Before/After" and the page number. I'd like the same feature for duplication. For example, if I select pages 15, 16, and 17, and choose the duplicate icon, it would be nice to get a prompt where I want to add them...:-)
Thanks!
Classic_2019.pdf