I noticed that also for PC version of Kindle app.. that it only does "old type" of sync (= furthest read), IIRC 1st gen Paperwhite also syncs the same way (it never got update that introduces "most recent" type of sync ??). Smartphone apps and Kindle PW2 and newer devices all do "most recent" sync.
So,thas's a problem if you're re-read a PDOC book, and you will have to "clear the furthest page read" data (from "Manage Your Content and Devices" section of Amazon website) to be able to start over. Since that option is hidden for PDOCs you will have to use bookmarklet (use the "MYK:CFPR3" version) from
this website which adds "clearFRP!" button next to each PDOC title on Amazon website.
That still leaves the problem that you'll probably have each time you jump to the end of a book to view things like glossary, ToC, About Author and then go back to "real reading position". But for that you could possibly also do "clearing the position on Amazon site then doing a sync on smartphone or Kindle eInk device" as a (annoying) workaround.
As long you're reading books from start to finish without jumping around backwards or forwards the "computer<>others" sync should work.