Hi, I got a ESPON XP-625, using IOS 10.9.5.
I used the german paper size "postkarte" (10x15 cm) once.
For the next print, this size was no longer available, but just in Lightroom.
In all other applications this size could be used.
Driver is up to date, I also updated Lightroom ,a after this, but nothing changed.
It is necessary to go to the page setup dialog which activates the printer driver settings to choose the paper size. Some paper sizes are only available when you haven't select the option for borderless printing. At least on my printer I have much larger choice of paper sizes when I'm not choosing borderless printing. Don't know if any of this helps. Just a couple of suggestions.