Some Patrologia Graeca volumes (e.g. vol 1 Intro & Commentary) do not appear to support viewable page numbers even though the page and volume/page data types are supported (the drop-down hides the "Emphasize" drop-menu, "Markers" is simply not there):
Other volumes (e.g. vol 14 intro & commentary) do:
Is there a reason, or is there some metadata issue with some volumes of PG?