I have a number of "zones" described by polygons that I use to produce a set of larger scale maps that I used to export into a pdf.
This has stopped working (when I moved to 2.4 ??) and now I always get just one item in the pdf (the one currently visible in preview). Each item consists of two pages: A map on the first page and two tables on the second page. The idea being that when one prints the pdf two sided then you get a map and the tables on the back.