printer page orientation

printer page orientation

Menu/Format/Page [Page]

Probably another case of Mac/OSX/Sierra or…/US paper size…
You cannot expect the user to expend his most valuable time for wording a clear question!

Surely, that was my first mind, but who knows?

Recently LibreOffice has started changing page orientation from Portrait to Landscape.
I have been unsuccessful in finding a way to correct this.
How or where can the Page Setup be changed or corrected?

Thank you for this answer.