Print rotation issue

I have recently setup a Brother QL-710W printer for making labels from Filemaker Go, but have run into a strange page setup problem.  It is a label printer that is AirPrint enabled, which allows printing from iOS devices.  The printer seems to be working fine, but I have a strange problem when printing the same layout from FM Go (on an iPhone), whereas it is fine using FM Pro.  

The problem seems to be that the FM Go inappropriately rotates the page from landscape to portrait causing the page to get truncated. (I run a page setup script ahead of time to set the non-standard page size and orientation)  

What's even weirder is that I can work around the problem if, on the FM Go print dialog, I choose "PDF > View" and then print this; but not if I choose "Print" directly within the FM Go dialog. Also if I choose the "Print" option first, and then later go back choose the "PDF > View" option then the rotation will also have changed to portrait and the image is truncated.  

It seems as though the "Print" button is changing the rotation back to portrait (even though it is not selected) and it comes out that way on the subsequent print out or when viewing a PDF version. 

As any one had print rotation issues from Filemaker Go?