My publisher (Lulu) gives the following instruction in their creator guide:
Print-on-demand printers tend to print landscape pages sideways, so even if you are creating a wide format book (9 x 7 in), the uploaded source document page orientation must be set to Portrait, with page dimensions defined with the wider width than height.
I have tied numerous ways to change my entire document from landscape to portrait and simultaneously define the width as 11" and the height as 8.5" - No matter how I try this, Indesign automatically changes the orientation to landscape when the page is wider than it is tall. Is it possible to set orientation to Portrait with page dimensions defined as wider width than height?
You need to ask program questions in the forum for the program you are using To ask in the forum for your program please start at https://community.adobe.com/ Moving from Using the Community (which is about the forums) to the correct forum... Mod
Potrait with width wider than height is landscape. I wouls see it that way, that they express their requirements unclear. Provide them your work in natural orientation. Before giving your ok ask for the custumer service to have a look on your files.