This is a problem I never have experienced before. Nothing has changed with my set-up in terms of hardware or software used but after recently having updated my computer Acrobat Reader is misbehaving when I try to print documents.
The orientation feature does no longer work properly. Only when using the Auto selection under Orientation will the program understand to print in Landscape orientation. Selecting Landscape does not do anything whatsoever. It just keeps printing in Portrait mode.
Also, and this may be related to it, I have noticed that, in contrast to another computer of mine, when printing, the computer continues to believe that I am printing in Letter format rather than A4 format, and creates all kinds of problems around this. Having reinstalled all software and drivers for my printer, an HP m477fdw didnt sort the problem out, but at this stage I have at least managed to get rid of the Letter problem, which really shouldnt be there in the first place.
Any idea of what this Orientation issue when printing may be all about?