Potentially relevant information:
Computer is Windows11
I’m using Libre Office version 25.8.1.1 (X86_64)
Ctrl-P opens the printer driver, which correctly identifies the printer as Epson XP-900. Layout Tab shows that Portrait, Print on both sides and Flip on long edge correctly selected. Advanced on the same Tab identifies itself as Microsoft IPP Class Driver Advanced Document Setting - it also shows that A4 paper size is correctly selected.
The issue: A 5 page document was printed with pages 2, and 4 printed upside down (ie. as though Flip on short edge had been selected - but it had not).
As a silly check, I next printed again with Print on short edge to see it that would do the opposite of what it stated. Nope, it did print with the pages 2 and 4 upside down.
I’ve been using Libre Office since 25th April 2025, and Open Office for many years before that. I’ve never had this problem before. The only (again silly) variable I can think of is that last week I finally and very reluctantly moved to Windows11 (on a brand new computer), having got on well with Windows10.
Final check: Print with Open Office version 4.1.15 Nope, same problem.
Suggestions greatly appreciated.